ICM Reference

General Parameters

The fields in the following table are all used with all cloud providers, and some are used with vSphere and Preexisting as well.

The two rightmost columns indicate whether each parameter is required in every deployment or optional, and whether it must be included (when used) in either defaults.json or definitions.json, is recommended for one file or the other, or can be used in either. For example,

• A single deployment is always on a single selected provisioning platform (even if subsequently merged with another to create a multiprovider deployment), therefore the Provider parameter is required and must be in the defaults file.

• Each node type must be specified but a deployment can include multiple node types, thus the Role parameter is required in each definition in the definitions file.

• Because each node that runs InterSystems IRIS must have a license, but other nodes don’t need one, the LicenseKey setting is required and generally appears in the appropriate definitions in the definitions file.

• At least one container must be deployed on each node in the deployment, but a single container may be deployed on all the nodes (for instance iris/iris-arm64 across a sharded cluster consisting of DATA nodes only) or different containers on different node types (iris/iris-arm64 on DM and AM, webgateway on WS, arbiter on AR in a distributed cache cluster). For this reason the DockerImage parameter is required and can appear in the defaults file, the definitions file, or both (to specify a default image but override it for one or more node types).

• Like the image to be deployed, the size of the OS volume can be specified for all nodes in the defaults file, for one or more node types in the definitions file, or in both, but because it has a default it is optional.

Security-related Parameters

The parameters in the following table are used to provide access and identify required files and information so that ICM can communicate securely with the provisioned nodes and deployed containers. They are all required, in the defaults file only.

• For information about using scripts provided with ICM to generate these files, see Obtain Security-Related Files in the “Using ICM” chapter.

• For information about how ICM uses the security files you provide to communicate securely with provisioned nodes and services on them, see ICM Security in this chapter

• For general information about using the SSH protocol, see SSH PROTOCOLOpens in a new tab from SSH Communications Security.

• For information about Docker security. including the use of TLS certificates with Docker, see Docker securityOpens in a new tab in the Docker documentation.

• For general information about using TLS with InterSystems IRIS, see InterSystems TLS GuideOpens in a new tab and The InterSystems Public Key InfrastructureOpens in a new tab. For information about the contents of the file identified by the SSLConfig parameter, see Create a Client ConfigurationOpens in a new tab.

• For information about the use of TLS to secure connections between mirror members, see Securing Mirror Communication with TLS SecurityOpens in a new tab in the High Availability Guide.

Port and Protocol Parameters

Typically, the defaults for these parameters are sufficient. For information about two use cases in which you may need to specify some of these parameters, see Ports in the appendix “Using ICM with Custom and Third-Party Containers” and Ports in the appendix “Deploying on a Preexisting Cluster”.

* If ICM is in container mode (Containerless is false or absent) and Overlay is set to weave (see General Parameters), this port is closed in the node’s firewall.

CPF Parameters

When using a configuration merge file specified by the UserCPF property to customize the CPF of one or more InterSystems IRIS instances during deployment, as described in Deploying with Customized InterSystems IRIS Configuration Parameters, you cannot include certain CPF settings, because ICM needs to read their values before it adds them to the CPF at a later stage. You should therefore customize these settings by specifying the following parameters (described in General Parameters and Port and Protocol Parameters) in your configuration files:

Provider-Specific Parameters

The tables in this section list parameters used by ICM that are specific to the various cloud providers. Some of these parameters are used with more than one provider; for example, the InstanceType, ElasticIP, and VPCId parameters can be used in both AWS and Tencent deployments. Some provider-specific parameters have different names but the same purpose, for example AMI and InstanceType for AWS, Image and MachineType for GCP, and ImageId and InstanceType for Tencent, whereas there are four Azure parameters corresponding to each of these.

Like the General Parameters table, the tables in this section indicate whether each parameter is required in every deployment or optional, and whether it must be included (when used) in either defaults.json or definitions.json, is recommended for one file or the other, or can be used in either. For examples of each type, see General Parameters.

Device Name Parameters

The parameters listed in the following specify the device files under /dev that represent the persistent volumes created by ICM for use by InterSystems IRIS. For information about these persistent volumes and a table of provider and OS-specific default values for these parameters, see Storage Volumes Mounted by ICM. For PreExisting deployments, see Storage Volumes in the “Deploying on a Preexisting Cluster” appendix.

Alphabetical List of User Parameters

The following table lists all of the parameters discussed in the preceding tables in this section in alphabetical order, with links to the table(s) containing their definition.

Role DATA: Sharded Cluster Data Node

As described in Overview of InterSystems IRIS ShardingOpens in a new tab and other sections of the “Horizontally Scaling for Data Volume with Sharding” chapter of the Scalability Guide, a typical sharded cluster consists only of data nodes, across which the sharded data is partitioned, and therefore requires only a DATA node definition in the definitions.json file. If DATA nodes are defined, the deployment must be a sharded cluster, and the only other node type that can be defined with them is COMPUTE.

DATA nodes can be mirrored if provisioned in a number matching the MirrorMap setting in their definition, as described in Rules for Mirroring. The DATA nodes in a cluster must be either all mirrored or all nonmirrored.

The only distinction between data nodes in a sharded cluster is that the first node configured (known as node 1) stores all of the nonsharded data, metadata, and code for the cluster in addition to its share of the sharded data. The difference in storage requirements, however, is typically very small. Because all data, metadata, and code is visible on any node in the cluster, application connections can be load balanced across all of the nodes to take greatest advantage of parallel query processing and partitioned caching. A load balancer may be assigned to DATA nodes; see Role LB: Load Balancer.

Role COMPUTE: Sharded Cluster Compute Node

For advanced use cases in which extremely low query latencies are required, potentially at odds with a constant influx of data, compute nodes can be added to a sharded cluster to provide a transparent caching layer for servicing queries, separating the query and data ingestion workloads and improving the performance of both. (For more information see Deploy Compute Nodes for Workload Separation and Increased Query ThroughputOpens in a new tab in the Scalability Guide.)

Adding compute nodes yields significant performance improvement only when there is at least one compute node per data node, so you should define at least as many COMPUTE nodes as DATA nodes; if the number of DATA nodes in the definitions file is greater than the number of COMPUTE nodes, ICM issues a warning. Configuring multiple compute nodes per data node can further improve the cluster’s query throughput, and the recommended best practice when doing so is to configure the same number of compute nodes for each data node, so ICM distributes the defined COMPUTE nodes as evenly as possible across the DATA nodes.

Because COMPUTE nodes support query execution only and do not store any data, their instance type and other settings can be tailored to suit those needs, for example by emphasizing memory and CPU and keeping storage to the bare minimum. Because they do not store data, COMPUTE nodes cannot be mirrored.

A load balancer may be assigned to COMPUTE nodes; see Role LB: Load Balancer.

Role DM: Distributed Cache Cluster Data Server, Standalone Instance, Shard Master Data Server

If multiple nodes of role AM and a DM node (nonmirrored or mirrored) are specified, they are deployed as an InterSystems IRIS distributed cache cluster, with the former serving as application servers and the latter as an data server.

A node of role DM (nonmirrored or mirrored) deployed by itself becomes a standalone InterSystems IRIS instance.

If a DM node (mirrored or nonmirrored), DS nodes (mirrored or nonmirrored), and (optionally) QS nodes are specified, they are deployed as a namespace-levelOpens in a new tab sharded cluster.

Role DS: Shard Data Server

Under the namespace-levelOpens in a new tab architecture, a data shard stores one horizontal partition of each sharded table loaded into a sharded cluster. A node hosting a data shard is called a shard data server. A cluster can have two or more shard data servers up to over 200. Shard data servers can be mirrored by deploying an even number and specifying mirroring.

Role QS: Shard Query Server

Under the namespace-level architecture, shard query servers provides query access to the data shards to which they are assigned, minimizing interference between query and data ingestion workloads and increasing the bandwidth of a sharded cluster for high volume multiuser query workloads. If shard query servers are deployed they are assigned round-robin to the deployed shard data servers. Shard query servers automatically redirect application connections when a mirrored shard data server fails over.

If QS nodes are defined but DS nodes are not, ICM responds with an arror like the following:

Shard Query Server (role 'QS') requires at least one Shard Data Server (role 'DS')

Role AM: Distributed Cache Cluster Application Server

If multiple nodes of role AM and a DM node are specified, they are deployed as an InterSystems IRIS distributed cache cluster, with the former serving as application servers and the latter as a data server. When the data server is mirrored, application connection redirection following failover is automatic.

A load balancer may be assigned to AM nodes; see Role LB: Load Balancer.

Role AR: Mirror Arbiter

When DATA nodes (sharded cluster DATA nodes), a DM node (distributed cache cluster data server, stand-alone InterSystems IRIS instance, or namespace-level shard master data server), or DS nodes (namespace-level shard data servers) are mirrored, deployment of an arbiter node to facilitate automatic failover is highly recommended. One arbiter node is sufficient for all of the mirrors in a cluster; multiple arbiters are not supported and are ignored by ICM, as are arbiter nodes in a nonmirrored cluster.

The AR node does not contain an InterSystems IRIS instance, using a different image to run an ISCAgent container. This arbiter image must be specified using the DockerImage field in the definitions file entry for the AR node; for more information, see The icm run Command.

For more information about the arbiter, see the “MirroringOpens in a new tab” chapter of the High Availability Guide.

Role WS: Web Server

A deployment may contain any number of web servers. Each web server node contains an InterSystems Web Gateway installation along with an Apache web server. ICM populates the remote server list in the InterSystems Web Gateway as follows:

• If DATA and COMPUTE nodes are deployed (node-level sharded cluster), all of the DATA and COMPUTE nodes, or all of the DATA nodes if no COMPUTE nodes are deployed.

• If AM nodes are deployed (distributed cache cluster), all of the AM nodes.

• Otherwise, the DM node (standalone instance or namespace-level sharded cluster).

  Note:

  If deploying a namespace-level sharded cluster with a web server tier, you can manually deploy a custom or third-party load balancer to distribute connections across the DS and (if they exist) QS nodes of the cluster (as recommended in Deploying the Namespace-level ArchitectureOpens in a new tab in the Scalability Guide) and manually edit the Web Gateway configurations to populate the remote server lists with the load balancer address (for more information, see Mirrored Configurations, Failover, and Load BalancingOpens in a new tab in the Web Gateway Guide).

For mirrored DATA and DM nodes, a mirror-aware connection is created, and application connection redirection following failover is automatic. Communication between the web server and the remote servers is configured to run in TLS mode.

A load balancer may be assigned to WS nodes; see Role LB: Load Balancer.

The WS node does not contain an InterSystems IRIS instance, using a different image to run a Web Gateway container. As described in The icm run Command, the webgateway image can be specified by including the DockerImage field in the WS node definition in the definitions.json file, for example:

{
    "Role": "WS",
    "Count": "3",
    "DockerImage": "intersystems/webgateway:latest-em",
    "ApplicationPath": "/acme",
    "AlternativeServers": "LoadBalancing"
}

If the ApplicationPath field is provided, its value is used to create an application path for each instance of the Web Gateway. The default server for this application path is assigned round-robin across Web Gateway instances, with the remaining remote servers making up the alternative server pool. For example, if the preceding sample WS node definition were part of a distributed cache cluster with three AM nodes, the assignments would be like the following:

The AlternativeServers field determines how the Web Gateway distributes requests to its target server pool. Valid values are LoadBalancing (the default) and FailOver. This field has no effect if the ApplicationPath field is not specified.

For information about using the InterSystems Web Gateway, see the Web Gateway GuideOpens in a new tab.

Role SAM: System Alerting and Monitoring Node

Defining a SAM node adds the System Alerting and Monitoring (SAM) cluster monitoring solution to a deployment. For information about adding SAM, see Monitoring in ICM; for complete information about SAM, see the System Alerting and Monitoring GuideOpens in a new tab.

Role LB: Load Balancer

ICM automatically provisions a predefined load balancer node when the provisioning platform is AWS, GCP, Azure, or Tencent, and the definition of nodes of type DATA, COMPUTE, DM, AM, or WS in the definitions file sets LoadBalancer to true. For a generic load balancer for VM or CN nodes, additional parameters must be provided.

Predefined Load Balancer

For nodes of role LB, ICM configures the ports and protocols to be forwarded as well as the corresponding health checks. Queries can be executed against the deployed load balancer the same way one would against a data node in a sharded cluster or a distributed cache cluster application server.

To add a load balancer to the definition of DATA, COMPUTE, DM, AM, or WS nodes, add the LoadBalancer field, for example:

{
    "Role": "AM",
    "Count": "2",
    "LoadBalancer": "true"
}

The following example illustrates the nodes that would be created and deployed given this definition:

$ icm inventory
Machine           IP Address    DNS Name                              Region   Zone
-------           ----------    --------                              ------   ----
ANDY-AM-TEST-0001 54.214.230.24 ec2-54-214-230-24.amazonaws.com       us-west1 c
ANDY-AM-TEST-0002 54.214.230.25 ec2-54-214-230-25.amazonaws.com       us-west1 c
ANDY-LB-TEST-0000 (virtual AM)  ANDY-AM-TEST-1546467861.amazonaws.com us-west1 c

Queries against this cluster can be executed against the load balancer the same way they would be against the AM nodes.

Predefined load balancers for mirrored DATA and DM nodes are mirror-aware and always direct traffic to the current primary.

The LoadBalancer field can be added to more than one definition in a deployment; for example a distributed cache cluster can contain AM nodes receiving load-balanced connections from a WS tier that receives load-balanced application connections.

Currently, a single automatically provisioned load balancer cannot serve multiple node types (for example, both DATA and COMPUTE nodes), so each requires its own load balancer. This does not preclude the user from manually deploying a custom or third-party load balancer to serve the desired roles. Another useful approach is to provision a load balancer for WS nodes, which can then distribute application connections across multiple node types as described in Role WS: Web Server.

Note:

When provisioning on AWS, you can specify a load balancer of type “internal” by setting LoadBalancerInternal to True in the definition in which LoadBalancer is set to True.

Generic Load Balancer

A load balancer can be added to VM (virtual machine) and CN (container) nodes by providing the following additional keys:

• ForwardProtocol

• ForwardPort

• HealthCheckProtocol

• HealthCheckPath

• HealthCheckPort

The following is an example:

{
    "Role": "VM",
    "Count": "2",
    "LoadBalancer": "true",
    "ForwardProtocol": "tcp",
    "ForwardPort": "443",
    "HealthCheckProtocol": "http",
    "HealthCheckPath": "/csp/status.cxw",
    "HealthCheckPort": "8080"
}

ForwardPort can be a comma-separated list of ports to forward, with the condition that all of the forwarded ports share the same ForwardProtocol.

More information about these keys can be found in the Ports and Protocol Parameters table in “ICM Configuration Parameters”.

Role VM: Virtual Machine Node

A cluster may contain any number of virtual machine nodes. A virtual machine node provides a means of allocating host nodes which do not have a predefined role within an InterSystems IRIS cluster. Docker is not installed on these nodes, though users are free to deploy whatever custom or third-party software (including Docker) they wish.

The following commands are supported on the virtual machine node:

• icm provision

• icm unprovision

• icm inventory

• icm ssh

• icm scp

A load balancer may be assigned to VM nodes; see Role LB: Load Balancer.

Role CN: Container Node

A cluster may contain any number of container nodes. A container node is a general purpose node with Docker installed.

You can add InterSystems API Manager (IAM) to any deployment by defining a CN node and including the IAM and IAMImage fields; for more information, see Deploying InterSystems API Manager (IAM) in the “ICM Reference” chapter. You can also deploy any custom and third-party containers you wish on a CN node; iris (InterSystems IRIS) containers will not be deployed if specified. All ICM commands are supported for container nodes, but most will be filtered out unless they use the -container option to specify a container other than iris, or either the -role or -machine option to limit the command to CN nodes (see ICM Commands and Options).

A load balancer may be assigned to CN nodes; see Role LB: Load Balancer. CN nodes cannot be deployed in containerless mode.

Role BH: Bastion Host

You may want to deploy a configuration that offers no public network access. If you have an existing private network, you can launch ICM on a node on that network and deploy within it. If you do not have such a network, you can have ICM configure a private subnet and deploy your configuration on it. Since ICM is not running within that private subnet, however, it needs a means of access to provision, deploy, and manage the configuration. The BH node serves this purpose.

A bastion host is a host node that belongs to both the private subnet configured by ICM and the public network, and can broker communication between them. To use one, you define a single BH node in your definitions file and set PrivateSubnet to true in your defaults file. For more information, see Deploying on a Private Network.

Rules for Mirroring

All data nodes in a sharded cluster must be mirrored, or all unmirrored. This requirement is reflected in the following ICM topology validation rules.

When the Mirror field is set to false in the defaults file (the default), mirroring is never configured, and provisioning fails if more than one DM node is specified in the definitions file.

When the Mirror field is set to true, mirroring is configured where possible, and the mirror roles of the DATA, DS, or DM nodes (primary, backup, or DR async) are determined by the value of the MirrorMap field (see General Parameters) in the node definition, as follows:

• If MirrorMap is not included in the relevant node definition, the nodes are configured as mirror failover pairs using the default MirrorMap value, primary,backup:

  • If an even number of DATA or DS nodes is defined, they are all configured as failover pairs; for example, specifying six DATA nodes deploys three data node mirrors containing failover pairs and no DR asyncs. If an odd number of DATA or DS nodes is defined, provisioning fails.

  • If two DM nodes are defined, they are configured as a failover pair; if any other number is defined, provisioning fails.

• If MirrorMap is included in the node definition, the nodes are configured according to its value, as follows:

  • The number of DATA or DS nodes must be a multiple of the number of roles specified in the MirrorMap value or fewer. For example, suppose the MirrorMap value, is primary,backup,async, as shown:

    "Role": "DATA",
    "Count": "",
    "MirrorMap": "primary,backup,async"
    
    

    

    In this case, DATA or DS nodes would be configured as follows:

    Value of Count	Result
    3 or multiples of 3	One or more mirrors containing a failover pair and a DR async
    2	A single mirror containing a failover pair
    1, 4 or more but not multiples of 3	Provisioning fails

  • The number of DM nodes must be the same as the number of roles specified in the MirrorMap value or fewer; if a single DM node is specified, provisioning fails.

• If more than one AR (arbiter) node is specified, provisioning fails. (While a best practice, use of an arbiter is optional, so an AR node need not be included in a mirrored configuration.)

All asyncs deployed by ICM are DR asyncs; reporting asyncs are not supported. Up to 14 asyncs can be included in a mirror. For information on mirror members and possible configurations, see Mirror ComponentsOpens in a new tab in the High Availability Guide.

There is no relationship between the order in which DATA, DS, or DM nodes are provisioned or configured and their roles in a mirror. Following provisioning, you can determine which member of each pair is the intended primary failover member and which the backup using the icm inventory command. To see the mirror member status of each node in a deployed configuration when mirroring is enabled, use the icm ps command.

Nonmirrored Configuration Requirements

A nonmirrored cluster consists of the following:

• One or more DATA (data nodes in a sharded cluster).

• If DATA nodes are included, zero or more COMPUTE (compute nodes in a sharded cluster); best practices are at least as many COMPUTE nodes as DATA nodes and the same number of COMPUTE nodes for each DATA node.

• If no DATA nodes are included:

  • Exactly one DM (distributed cache cluster data server, standalone InterSystems IRIS instance, shard master data server in namespace-levelOpens in a new tab sharded cluster).

  • Zero or more AM (distributed cache cluster application server).

  • Zero or more DS (shard data servers in namespace-level sharded cluster).

  • Zero or more QS (shard query servers in namespace-level sharded cluster, cannot be deployed without corresponding DS nodes)

• Zero or more WS (web servers).

• Zero or more LB (load balancers).

• Zero or more VM (virtual machine nodes).

• Zero or more CN (container nodes).

• Zero or one BH (bastion host).

• Zero AR (arbiter node is for mirrored configurations only).

The relationships between some of these nodes types are pictured in the following examples.

Mirrored Configuration Requirements

A mirrored cluster consists of:

• If DATA nodes (data nodes in a node-level sharded cluster) are included:

  • A number of DATA matching the MirrorMap value, default or explicit, as described in Rules for Mirroring.

  • Zero or more COMPUTE (compute nodes in a node-level sharded cluster); best practices are at least one COMPUTE node per DATA node mirror, and the same number of COMPUTE nodes for each DATA node mirror.

• If no DATA nodes are included:

  • Two DM as a mirrored shard master data server in a namespace-level sharded cluster, data server in a distributed cache cluster, or standalone InterSystems IRIS instance, or more than two if DR asyncs are specified by the MirrorMap field, as described in Rules for Mirroring.

  • If a namespace-level sharded cluster:

    • A number of DS (shard data servers) matching the MirrorMap value, default or explicit, as described in Rules for Mirroring.

    • Zero or more QS (shard query servers), as described in the foregoing for COMPUTE nodes.

  • Zero or more AM as application servers in a distributed cache cluster.

• Zero or one AR (arbiter node is optional but recommended for mirrored configurations).

• Zero or more WS (web servers).

• Zero or more LB (load balancers).

• Zero or more VM (virtual machine nodes).

• Zero or more CN (container nodes).

• Zero or one BH (bastion host).

The following fields are required for mirroring:

• Mirroring is enabled by setting key Mirror in your defaults.json file to true.

  "Mirror": "true"
  

  

• To include DR asyncs in DATA, DS, or DM mirrors, you must include the MirrorMap field in your definitions file to specify that those beyond the first two are DR async members. The value of MirrorMap must always begin with primary,backup, for example:

  "Role": "DM",
  "Count": "5”,
  "MirrorMap": "primary,backup,async,async,async",
  ...
  

  

  For information on the relationship between the MirrorMap value and the number of DATA, DS, or DM nodes defined, see Rules for Mirroring. MirrorMap can be used in conjunction with the Zone and ZoneMap fields to deploy async instances across zones; see Deploying Across Multiple Zones.

Automatic LB deployment (see Role LB: Load Balancer) is supported for providers AWS, GCP, Azure, and Tencent; when creating your own load balancer, the pool of IP addresses to include are those of DATA, COMPUTE, AM, or WS nodes, as called for by your configuration and application.

The relationships between some of these nodes types are pictured in the following examples.

Host Node Communication

A host node is the host machine on which containers are deployed. It may be virtual or physical, running in the cloud or on-premises.

ICM uses SSH to log in to host nodes and remotely execute commands on them, and SCP to copy files between the ICM container and a host node. To enable this secure communication, you must provide an SSH public/private key pair and specify these keys in the defaults.json file as SSHPublicKey and SSHPrivateKey. During the configuration phase, ICM disables password login on each host node, copies the private key to the node, and opens port 22, enabling clients with the corresponding public key to use SSH and SCP to connect to the node.

Other ports opened on the host machine are covered in the sections that follow.

Docker

During provisioning, ICM downloads and installs a specific version of Docker from the official Docker web site using a GPG fingerprint. ICM then copies the TLS certificates you provide (located in the directory specified by the TLSKeyDir field in the defaults file) to the host machine, starts the Docker daemon with TLS enabled, and opens port 2376. At this point clients with the corresponding certificates can issue Docker commands to the host machine.

Weave Net

During provisioning, ICM launches Weave Net with options to encrypt traffic and require a password (provided by the user) from each machine joining the Weave network. To enable these options, set WeavePassword to the any value other than null in the defaults.json file.

InterSystems IRIS

For a comprehensive overview of InterSystems IRIS security, see About InterSystems SecurityOpens in a new tab.

Private Networks

ICM can deploy on an existing private network (not accessible from the Internet) if you configure the access it requires. ICM can also create a private network on which to deploy and configure its own access through a bastion host. For more information on using private networks, see Deploying on a Private Network.

Deploying Across Multiple Regions on GCP

To deploy across multiple regions on GCP, specify the desired regions as a comma-separated list in the Region field in the defaults file, as shown:

{
    "Provider": "GCP",
    "Label": "Sample",
    "Tag": "multi",
    "Region": "us-east1,us-west1",
    "Zone": "us-east1-b,us-west1-a",
    ...
}

By default, nodes within each definition are assigned a region in round-robin fashion. For example, suppose you are deploying with the fields shown above in defaults.json and the following definitions.json:

[
  {
    "Role": "DATA",
    "Count": "2"
  },
  {
    "Role": "AR",
    "Count": "1",
    "DockerImage": "intersystems/arbiter:latest-em"
  }
]

In this case, the output of the icm inventory command might look like this:

$ icm inventory
Machine               IP Address    DNS Name              Region    Zone
-------               ----------    --------              ------    ----
Acme-AR-multi-0001    35.179.173.90 acmear1.google.com    us-east1     b
Acme-DATA-multi-0001- 35.237.131.39 acmedata1.google.com  us-east1     b
Acme-DATA-multi-0002+ 35.233.223.64 acmedata2.google.com  us-west1     a

For control over the regions that nodes are deployed in, you can use the RegionMap field to map the defined nodes to the specified regions. When RegionMap is included in a node definition, ZoneMap (described in the preceding section, Deploying Across Multiple Zones) must also be included to map the node or nodes to the desired zone or zones. For example, suppose you are deploying a mirror containing a failover pair and a DR async with an arbiter, and you want the failover pair in one region but in different zones, and the async and arbiter in a different region and also in different zones. The files you might use and the output you might see from the icm inventory and icm ps commands are shown in the following:

defaults.json

{
    "Provider": "GCP",
    "Label": "Sample",
    "Tag": "multi",
    "Region": "us-east1,us-west1",
    "Zone": "us-east1-a,us-east1-b,us-west1-a,us-west1-b",
    ...
}

definitions.json

[
  {
    "Role": "DATA",
    "Count": "3",
    "MirrorMap": "primary,backup,async",
    "RegionMap": "1,1,2",
    "ZoneMap": "1,2,3",
  },
  {
    "Role": "AR",
    "Count": "1",
    "DockerImage": "intersystems/arbiter:latest-em",
    "RegionMap": "2",
    "ZoneMap": "4"
  }
]

icm inventory

Machine               IP Address    DNS Name              Region    Zone
-------               ----------    --------              ------    ----
Acme-AR-multi-0001    35.179.173.90 acmear1.google.com    us-west1     b
Acme-DATA-multi-0001+ 35.237.131.39 acmedata1.google.com  us-east1     b
Acme-DATA-multi-0002- 35.233.223.64 acmedata2.google.com  us-east1     a
Acme-DATA-multi-0003  35.166.127.82 acmedata3.google.com  us-west1     a

icm ps

Machine              IP Address    Container Status Health  Mirror    Image
-------              ----------    --------- ------ ------  ------    -----
Acme-AR-multi-0001   35.179.173.90 arbiter   Up     healthy           intersystems/arbiter:latest-em
Acme-DATA-multi-0001 35.237.131.39 iris      Up     healthy PRIMARY   intersystems/iris:latest-em
Acme-DATA-multi-0002 35.233.223.64 iris      Up     healthy BACKUP    intersystems/iris:latest-em
Acme-DATA-multi-0003 35.166.127.82 iris      Up     healthy CONNECTED intersystems/iris:latest-em

To use the Network field (see Google Cloud Platform (GCP) Parameters) to specify an existing network to use in a multiregion deployment, you must also use the GCP Subnet field to specify a unique subnet for each region specified by the Region field. For example, for a deployment on regions us-west1 and us-east1, as illustrated here, you might include the following in your defaults file:

"Network": "acme-network",
"Subnet": "acme-subnet-data-east,acme-subnet-data-west"

Deploying Across Multiple Regions on Azure

To deploy across multiple regions on Azure, specify the desired regions as a comma-separated list in the Location field in the defaults file, as shown:

{
    "Provider": "Azure",
    "Label": "Sample",
    "Tag": "multi",
    "Location": "East US,Central US",
    ...
}

By default, nodes within each definition are assigned a location in round-robin fashion. For example, suppose you are deploying with the fields shown above in defaults.json and the following definitions.json:

[
  {
    "Role": "DATA",
    "Count": "2"
  },
  {
    "Role": "AR",
    "Count": "1",
    "DockerImage": "intersystems/arbiter:latest-em"
  }
]

In this case, the output of the icm inventory command might look like this:

$ icm inventory
Machine               IP Address    DNS Name             Region    Zone
-------               ----------    --------             ------    ----
Acme-AR-multi-0001    35.179.173.90 acmear1.azure.com    East US    1
Acme-DATA-multi-0001- 35.237.131.39 acmedata1.azure.com  East US    1
Acme-DATA-multi-0001+ 35.233.223.64 acmedata2.azure.com  Central US 1

For control over the regions that nodes are deployed in, you can use the LocationMap field to map the defined nodes to the specified regions. When LocationMap is included in a node definition, ZoneMap (described in the preceding section, Deploying Across Multiple Zones) must also be included to map the node or nodes to the desired zone or zones. For example, suppose you are deploying a mirror containing a failover pair and a DR async with an arbiter, and you want the failover pair in one region but in different zones, and the async and arbiter in a different region and also in different zones. The files you might use and the output you might see from the icm inventory and icm ps commands are shown in the following. (Note that Azure zones are identified by the same integers in every region, so ZoneMap identifies only the desired zone within whatever region is specified by LocationMap.)

defaults.json

{
    "Provider": "Azure",
    "Label": "Sample",
    "Tag": "multi",
    "Location": "East US,Central US",
    "Zone": "1,2",
    ...
}

definitions.json

[
  {
    "Role": "DATA",
    "Count": "3",
    "MirrorMap": "primary,backup,async",
    "LocationMap": "1,1,2",
    "ZoneMap": "1,2,1"
  },
  {
    "Role": "AR",
    "Count": "1",
    "DockerImage": "intersystems/arbiter:latest-em",
    "RegionMap": "2",
    "ZoneMap": "2"
  }
]

icm inventory

Machine               IP Address    DNS Name             Region     Zone
-------               ----------    --------             ------     ----
Acme-AR-multi-0001    35.179.173.90 acmear1.azure.com    Central US 2
Acme-DATA-multi-0001+ 35.237.131.39 acmedata1.azure.com  East US    1
Acme-DATA-multi-0002- 35.233.223.64 acmedata2.azure.com  East US    2
Acme-DATA-multi-0003  35.166.127.82 acmedata3.google.com Central US 1

icm ps

Machine              IP Address    Container Status Health  Mirror    Image
-------              ----------    --------- ------ ------  ------    -----
Acme-AR-multi-0001   35.179.173.90 arbiter   Up     healthy           intersystems/arbiter:latest-em
Acme-DATA-multi-0001 35.237.131.39 iris      Up     healthy PRIMARY   intersystems/iris:latest-em
Acme-DATA-multi-0002 35.233.223.64 iris      Up     healthy BACKUP    intersystems/iris:latest-em
Acme-DATA-multi-0003 35.166.127.82 iris      Up     healthy CONNECTED intersystems/iris:latest-em

If you want to use an existing virtual network in a multiregion Azure deployment, you must include the ResourceGroupName and VirtualNetwork fields (see Microsoft Azure (Azure) Parameters) in the defaults file to specify a network for each region specified in the Location field, for example:

{
    "Provider": "Azure",
    "Label": "Sample",
    "Tag": "multi",
    "Location": "East US,Central US",
    "Zone": "1,2",
    "ResourceGroupName": "sample-resource-group",
    "VirtualNetworkName": "sample-vnet-east,sample-vnet-central"
    ...
}

The specified networks must have nonoverlapping address spaces. In the accompanying definitions file, each definition must include the Subnetname field specifying a unique subnet for each region specified by the Location field. For example, for the mirrored deployment illustrated in this section, if the defaults file included the ResourceGroupName and VirtualNetwork fields, the definitions file might look like the following. Because the AR definition deploys in the Central US region only, just one subnet is required in that definition.

[
  {
    "Role": "DATA",
    "Count": "3",
    "MirrorMap": "primary,backup,async",
    "RegionMap": "1,1,2",
    "ZoneMap": "1,2,1",
    "SubnetName": "acme-subnet-data-east,acme-subnet-data-central"
  },
  {
    "Role": "AR",
    "Count": "1",
    "DockerImage": "intersystems/arbiter:latest-em",
    "RegionMap": "2",
    "ZoneMap": "2",
    "SubnetName": "acme-subnet-arbiter-central"
  }
]

Deploying Across Multiple Regions on AWS and Tencent

To deploy across multiple regions on AWS and Tencent, ICM first provisions the needed infrastructure in the separate regions, then merges that infrastructure and deploys services on it as if it were preexisting infrastructure.

This procedure can also be used to deploy across multiple providers. In this discussion, “region” is used to indicate “region or provider”, with differences between multiprovider and AWS/Tencent multiregion noted as needed.

The procedure for creating merged multiregion deployments involves the following steps:

1. Provision the infrastructure in each region in separate ICM sessions.

2. Merge the multiregion infrastructure using the icm merge command.

3. Review the merged definitions.json file to reorder and update as needed.

4. Reprovision the merged infrastructure using the icm provision command.

5. Deploy services on the merged infrastructure as a Preexisting deployment using the icm run command.

6. When unprovisioning the infrastructure, issue the icm unprovision command separately in the original session directories.

Provision the Infrastructure

The separate sessions for provisioning infrastructure in each region (specified by the Region field) should be conducted in separate working directories within the same ICM container. For example, you could begin by copying the provided /Samples/AWS directory (see Define the Deployment in the “Using ICM” chapter) to /Samples/AWS/us-east-1 and /Samples/AWS/us-west–1. Specify the desired region, node definitions, and features to match the eventual multiregion deployment in the defaulta and definitions file for each. For example, if you want to deploy a mirror failover pair in one region and a DR async member of the mirror in another, include the appropriate region and zones and "Mirror": "true" in the defaults files, and define two DMs (for the failover pair) in one region in its definitions file, a third DM (for the async) in the other, and a single AR (arbiter) node in one or the other. Each defaults file in a multiregion deployment should have a unique Label and/or Tag to prevent resource conflicts; this is not necessary for multiprovider deployments. This example is shown in the following.

Note:

If a given definition doesn't satisfy topology requirements for a single-region deployment, for example a single DM node defined when Mirror is set to true, disable topology validation by including "SkipTopologyValidation": "true" in the defaults file, as shown in the /Samples/AWS/us-west-1/defaults.json.

/Samples/AWS/us-east-1

defaults.json

{
    "Provider": "AWS",
    "Label": "Sample",
    "Tag": "east1",
    "Region": "us-east-1",
    "Zone": "us-east1-a,us-east1-b",
    "Mirror": "true",
    ...
}

definitions.json

[
  {
    "Role": "DM",
    "Count": "2",
    "ZoneMap": "1,2"
  }
]

/Samples/AWS/us-west-1/

defaults.json

{
    "Provider": "AWS",
    "Label": "Sample",
    "Tag": "west1",
    "Region": "us-west-1",
    "Zone": "us-west1-a,us-west1-b",
    "Mirror": "true",
    "SkipTopologyValidation": "true"},
    ...
}

definitions.json

[
  {
    "Role": "DM",
    "Count": "1",
    "ZoneMap": "1"
  }
  {
    "Role": "AR",
    "Count": "1",
    "ZoneMap": "2"
  }
]

Use the icm provision command in each working directory to provision the infrastructure in each region. The output of the icm inventory command, executed in each directory, shows you the infrastructure you are working with, for example:

/Samples/AWS/us-east-1

$ icm inventory
Machine             IP Address    DNS Name                        Region    Zone
-------             ----------    --------                        ------    ----
Acme-DM-east1-0001+ 54.214.230.24 ec2-54-214-230-24.amazonaws.com us-east-1 a
Acme-DM-east1-0002- 54.129.103.67 ec2-54-129-103-67.amazonaws.com us-east-1 b

/Samples/AWS/us-west-1

$ icm inventory
Machine             IP Address    DNS Name                        Region    Zone
-------             ----------    --------                        ------    ----
Acme-AR-west1-0001  54.181.212.79 ec2-54-181-212-79.amazonaws.com us-west-1 b
Acme-DM-west1-0002  54.253.103.21 ec2-54-253-103-21.amazonaws.com us-west-1 a

Merge the Provisioned Infractructure

The icm merge command scans the configuration files in the current working directory and those in the additional directory or directories specified to create merged configuration files that can be used for a Preexisting deployment in a specified new directory. For example, to merge the definitions and defaults files in /Samples/AWS/us-east–1 and /Samples/AWS/us-west–1 into a new set in /Samples/AWS/merge, you would issue the following commands:

$ cd /Samples/AWS/us-east-1
$ mkdir ../merge
$ icm merge -options ../us-west1 -localPath /Samples/AWS/merge

In the icm merge command, -options specifies a comma-separated list of the provisioning directories to be merged with the local one, and --localPath specifies the destination directory for the merged definitions. (For more information on the -options option, which lets you include Docker arguments on the ICM command line, see Using ICM with Custom and Third-Party Containers.)

Review the Merged Definitions File

When you examine the new configuration files, you will see that Provider has been changed to PreExisting in the merged defaults file. (The previous Provider field and others have been moved into the definitions file; they are displayed by the icm inventory command, but otherwise have no effect.) The Label and/or Tag can be modified if desired.

The definitions in the merged definitions file have been converted for use with provider PreExisting. As described in Definitions File for PreExisting in the appendix “Deploying on a Preexisting Cluster”, the definitions.json file for a Preexisting deployment contains exactly one entry per node (rather than one entry per role with a Count field to specify the number of nodes of that role). Each node is identified by its IP address or fully-qualified domain name. Either the IPAddress or DNSName field must be included in each definition, as well as the SSHUser field. (The latter specifies a nonroot user with passwordless sudo access, as described in SSH in “Deploying on a Preexisting Cluster”.) In the merged file, the definitions have been grouped by region, or by provider in multiprovider deployments; they should be reordered to reflect desired placement of mirror members, if necessary, and a suitable mirror map defined (see Mirrored Configuration Requirements and Deploying Across Multiple Zones). After review, the definitions file for our example would look like this:

[
    {
        "Role":"DM",
        "IPAddress":"54.214.230.24",
        "LicenseKey": "ubuntu-sharding-iris.key",
        "SSHUser": "icmuser",
        "MirrorMap": "primary,backup,async"
    },
    {
        "Role":"DM",
        "IPAddress":"54.129.103.67",
        "LicenseKey": "ubuntu-sharding-iris.key",
        "SSHUser": "icmuser",
        "MirrorMap": "primary,backup,async"
    },
    {
        "Role":"DM",
        "IPAddress":"54.253.103.21",
        "LicenseKey": "ubuntu-sharding-iris.key",
        "SSHUser": "icmuser",
        "MirrorMap": "primary,backup,async"
    },
    {
        "Role":"AR",
        "IPAddress":"54.181.212.79",
        "SSHUser": "icmuser",
        "StartCount": "4"
    }
]

Reprovision the Merged Infrastructure

Reprovision the merged infrastructure by issuing the icm provision command in the new directory (/Samples/AWS/merge in the example). The output of the icm inventory command shows the merged infrastructure in one list:

$ icm inventory
Machine             IP Address     DNS Name                       Region    Zone
-------             ----------     --------                       ------    ----
Acme-DM-east1-0001+ 54.214.230.24 ec2-54-214-230-24.amazonaws.com us-east-1 a
Acme-DM-east1-0002- 54.129.103.67 ec2-54-129-103-67.amazonaws.com us-east-1 b
Acme-AR-west1-0001  54.181.212.79 ec2-54-181-212-79.amazonaws.com us-west-1 b
Acme-DM-west1-0002  54.253.103.21 ec2-54-253-103-21.amazonaws.com us-west-1 a

Deploy Services on the Merged Infrastructure

Use the icm run command to deploy services on your merged infrastructure, as you would for any deployment, for example

$ icm run
...
-> Management Portal available at: http://112.97.196.104.google.com:52773/csp/sys/UtilHome.csp
$ icm ps
Machine            IP Address    Container Status Health  Mirror    Image
-------            ----------    --------- ------ ------  ------    -----
Acme-AR-multi-0001 35.179.173.90 arbiter   Up     healthy           intersystems/arbiter:latest-em
Acme-DM-multi-0001 35.237.131.39 iris      Up     healthy PRIMARY   intersystems/iris:latest-em
Acme-DM-multi-0002 35.233.223.64 iris      Up     healthy BACKUP    intersystems/iris:latest-em
Acme-DM-multi-0003 35.166.127.82 iris      Up     healthy CONNECTED intersystems/iris:latest-em

Unprovision the Merged Infrastructure

When the time comes to unprovision the multiregion deployment, return to the original working directories to issue the icm unprovision command, and then delete the merged working directory. In our example, you would do the following:

$ cd /Samples/AWS/us-east-1
$ icm unprovision -force -cleanUp
...
...completed destroy of Acme-east1
$ cd /Samples/AWS/us-west-1
$ icm unprovision -force -cleanUp
...
...completed destroy of Acme-west1
$ rm -rf /Samples/AWS/merge

Deploy Within an Existing Private Network

If you deploy ICM on an existing private network and want to provision and deploy on that network, as shown in the following illustration, you need to add fields to the defaults and definitions files for the configuration you want to deploy.

To deploy on an existing private network, follow these steps:

1. Obtain access to a node that resides within the private network. This may require use of a VPN or intermediate host.

2. Install Docker and ICM on the node as described in Launch ICM in the “Using ICM” chapter.

3. Add the following fields to the defaults.json file:

   "PrivateSubnet": "true",
   "net_vpc_cidr": "10.0.0.0/16",
   "net_subnet_cidr": "10.0.2.0/24"
   

   

   The net_vpc_cidr and net_subnet_cidr fields (shown with sample values) specify the CIDRs of the private network and the node’s subnet within that network, respectively.

4. Add the appropriate common and provider-specific fields to the defaults.json file, as follows:

   Provider	Key	Description
   all	PrivateSubnet	Must be set to true
   	net_vpc_cidr	CIDR of the private network
   	net_subnet_cidr	CIDR of the ICM node’s subnet within the private network (see Note)
   GCP	Network	Google VPC
   	Subnet	Google subnetwork
   Azure	ResourceGroupName	AzureRM resource group
   	VirtualNetworkName	AzureRM virtual network
   	SubnetName	AzureRM subnet (see Note)
   AWS (see Note)	VPCId	AWS VPC ID
   	SubnetIds	Comma-separated list of AWS subnet IDs, one for each element specified by the Zone field.
   Tencent	VPCId	Tencent VPC ID
   	SubnetIds	Comma-separated list of Tencent subnet IDs, one for each element specified by the Zone field.

   Note:

   On Azure, ICM assigns a security group to the subnet specified by SubnetName, which could affect the behavior of unrelated machines on the subnet. For this reason, a dedicated subnet (as specified by a unique SubnetName and corresponding net_subnet_cidr) must be provided for every entry in the definitions file (but ResourceGroupName and VirtualNetworkName remain in the defaults file). This includes the BH definition when deploying a bastion host, as described in the following section.

   To deploy InterSystems IRIS within an existing private VPC on AWS, you must create a node within that VPC on which you can deploy and use ICM. If you want to reach this ICM host from outside the VPC, you can specify a route table and Internet gateway for ICM to use instead of creating its own. To do this, add the RouteTableId and InternetGatewayId fields to your defaults.json file, for example:

   "RouteTableID": "rtb-00bef388a03747469",
   "InternetGatewayId": "igw-027ad2d2b769344a3"
   

   

   When provisioning on GCP, the net_subnet_cidr field is descriptive, not proscriptive; it should be an address space which includes the node’s subnet, as well as any others within the network should have access to the deployed configuration.

5. Use icm provision and icm run to provision and deploy your configuration.

Bear the following in mind when deploying on a private network.

• Viewing web pages on any node within the private network, for example the Management Portal, requires a browser that also resides within the private network, or for which a proxy or VPN has been configured.

• Any DNS name shown in the output of ICM commands is just a copy of the local IP address.

• Private network deployment across regions or providers is currently not supported.

Deploy on a Private Network Through a Bastion Host

If you set the PrivateSubnet field to true in the defaults file but don't include the fields required to use an existing network, ICM creates a private network for you. You cannot complete the provisioning phase in this situation, however, because ICM is unable to configure or otherwise interact with the machines it just allocated. To enable its interaction with nodes on the private network it creates, ICM can optionally create a bastion host, a host node that belongs to both the private subnet and the public network and can broker communication between them.

To create a private network and a bastion host providing ICM with access to that network, add a definition for a single node of type BH to the definitions.json file, for example:

   {
       "Role": "DATA",
       "Count": "3"
   },
   {
       "Role": "BH",
       "Count": "1",
       "StartCount: 4"
   }

To deploy and use a bastion host with an existing private network, add a BH definition to the definitions file, as above, and include the fields necessary to specify the network in the defaults file (as describe in the previous section). ICM automatically sets the "PrivateSubnet" option to "true" when a BH node definition is included in definitions.json

The bastion host can be accessed using SSH, allowing users to tunnel SSH commands to the private network. Using this technique, ICM is able to allocate and configure compute instances within the private network from outside, allowing provisioning to succeed, for example:

$ icm inventory
Machine             IP Address     DNS Name                     Region   Zone
-------             ----------     --------                     ------   ----
Acme-BH-TEST-0004   35.237.125.218 218.125.237.35.bc.google.com us-east1 b
Acme-DATA-TEST-0001 10.0.0.2       10.0.0.2                     us-east1 b
Acme-DATA-TEST-0002 10.0.0.3       10.0.0.3                     us-east1 b
Acme-DATA-TEST-0003 10.0.0.4       10.0.0.4                     us-east1 b

Once the configuration is deployed, it is possible to run the ssh command against any node, for example:

# icm ssh -role DATA -interactive
ubuntu@ip-10.0.0.2:~$

If you examine the command being run, however, you can see that it is routed through the bastion host:

$ icm ssh -role DATA -interactive -verbose
ssh -A -t -i /Samples/ssh/insecure -p 3022 ubuntu@35.237.125.218
ubuntu@ip-10.0.0.2:~$

On the other hand, for other commands to succeed, ICM needs access to ports and protocols besides SSH. To do this, ICM configures tunnels between the bastion host and nodes within the cluster for Docker, JDBC, and HTTP. This allows commands such as icm run, icm exec, and icm sql to succeed.

Bear the following in mind when deploying a bastion host:

• The address of the configuration’s Management Portal is that of the bastion host.

• For security reasons, no private keys are stored on the bastion host.

• Any DNS name shown in the output of ICM commands is just a copy of the local IP address.

• Provisioning of load balancers in a deployment that includes a bastion host is not supported.

• Use of a bastion host with multiregion deployments (see Deploying Across Multiple Regions or Providers) and in distributed management mode (see the appendix “Sharing ICM Deployments”) are currently not supported.

  Note:

  When you create a custom VPC in the Google portal, you are required to create a default subnet. If you are provisioning with a bastion host and will use the subnet created by ICM, you should delete this default subnet before provisioning (or give it an address space that won't collide with the default address space 10.0.0.0/16).

System Alerting and Monitoring

System Alerting and Monitoring, or SAM, is a cluster monitoring solution for InterSystems IRIS® data platform. Whatever configuration and platform your InterSystems IRIS-based application runs on, you can monitor with SAM. For complete information about SAM, see the System Alerting and Monitoring GuideOpens in a new tab.

SAM is included in your ICM deployment when you include a SAM node in your definitions file; the DockerImage field is required and must specify the InterSystems sam image, as shown in the following:

[
    {
        "Role": "DM",
        "Count": "4",
        "LicenseKey": "ubuntu-sharding-iris.key"
    },
    {
        "Role": "SAM",
        "Count": "1",
        "DockerImage": "intersystems/sam:2.0"
    }
]

The SAM application comprises five containers. The SAM Manager container is deployed during the deployment phase (see The icm run Command).

The other four containers — Prometheus, Alertmanager, Grafana, and Nginx — are deployed during the provisioning phase (see The icm provision Command). The images from which these containers are deployed can be specified using the PrometheusImage, AlertmanagerImage, GrafanaImage, and NginxImage fields; their default values are shown in General Parameters.

Following successful deployment, a message like the example below is displayed:

$ icm run
...
-> SAM Portal available at: http://112.97.196.104.google.com:8080/api/sam/app/index.csp#

Deploying Third-party Monitoring with ICM

You can deploy the third-party monitoring package of your choice (or any other third-party package) as part of your ICM configuration. The following example shows how to use the icm ssh command to add Weave Scope monitoring to all of the hosts in a deployment:

icm ssh -command "sudo curl -L git.io/scope -o /usr/local/bin/scope 2>&1"
icm ssh -command "sudo chmod +x /usr/local/bin/scope"
icm ssh -command "sudo /usr/local/bin/scope launch 2>&1"

Following these commands, you can access Weave Scope through port 4040 on any of the hosts displayed by the icm inventory command, that is, at http://hostname:4040.

Host Node Restart and Recovery

When a cloud host node is shut down and restarted due to an unplanned outage or to planned action by the cloud provider (for example, for preventive maintenance) or user (for example, to reduce costs), its IP address and domain name may change, causing problems for both ICM and deployed applications (including InterSystems IRIS).

This behavior differs by cloud provider. GCP and Azure preserve IP address and domain name across host node restart by default, whereas this feature is optional on AWS and Tencent (see Elastic IP Feature).

Reasons a host node might be shut down include the following:

• Unplanned outage

  • Power outage

  • Kernel panic

• Preventive maintenance initiated by provider

• Cost reduction strategy initiated by user

Methods for intentionally shutting down host nodes include:

• Using the cloud provider user interface

• Using ICM:

  icm ssh -command 'sudo shutdown'
  

  

Correcting Time Skew

If the system time within the ICM containers differs from Standard Time by more than a few minutes, the various cloud providers may reject requests from ICM. This can happen if the container is unable to reach an NTP server on startup (initial or after being stopped or paused). The error appears in the terraform.err file as some variation on the following:

Error refreshing state: 1 error(s) occurred:

    # icm provision
    Error: Thread exited with value 1
    Signature expired: 20170504T170025Z is now earlier than 20170504T171441Z (20170504T172941Z   15 min.)
    status code: 403, request id: 41f1c4c3-30ef-11e7-afcb-3d4015da6526 doesn’t run for a period of time

The solution is to manually run NTP, for example:

ntpd -nqp pool.ntp.org

and verify that the time is now correct. (See also the discussion of the --cap-add option in Launch ICM.)

Timeouts Under ICM

When the target system is under extreme load, various operations in ICM may time out. Many of these timeouts are not under direct ICM control (for example, from cloud providers); other operations are retried several times, for example SSH and JDBC connections.

SSH timeouts are sometimes not identified as such. For instance, in the following example, an SSH timeout manifests as a generic exception from the underlying library:

# icm cp -localPath foo.txt -remotePath /tmp/
2017-03-28 18:40:19 ERROR Docker:324 - Error: 
java.io.IOException: com.jcraft.jsch.JSchException: channel is not opened. 
2017-03-28 18:40:19 ERROR Docker:24 - java.lang.Exception: Errors occurred during execution; aborting operation 
        at com.intersystems.tbd.provision.SSH.sshCommand(SSH.java:419) 
        at com.intersystems.tbd.provision.Provision.execute(Provision.java:173) 
        at com.intersystems.tbd.provision.Main.main(Main.java:22)

In this case the recommended course of action is to retry the operation (after identifying and resolving its proximate cause).

Note that for security reasons ICM sets the default SSH timeout for idle sessions at ten minutes (60 seconds x 10 retries). These values can be changed by modifying the following fields in the/etc/ssh/sshd_config file:

ClientAliveInterval 60
ClientAliveCountMax 10

Docker Bridge Network IP Address Range Conflict

For container networking, Docker uses a bridge network (see Use bridge networksOpens in a new tab in the Docker documentation) on subnet 172.17.0.0/16 by default. If this subnet is already in use on your network, collisions may occur that prevent Docker from starting up or prevent you from being able to reach your deployed host nodes. This problem can arise on the machine hosting your ICM container, your InterSystems IRIS cluster nodes, or both.

To resolve this, you can edit the bridge network’s IP configuration in the Docker configuration file to reassign the subnet to a range that is not in conflict with your own IP addresses (your IT department can help you determine this value). To make this change, add a line like the following to the Docker daemon configuration file:

"bip": "192.168.0.1/24"

If the problem arises with the ICM container, edit the file /etc/docker/daemon.json on the container’s host. If the problem arises with the host nodes in a deployed configuration, edit the file /ICM/etc/toHost/daemon.json in the ICM container; by default this file contains the value in the preceding example, which is likely to avoid problems with any deployment type except PreExisting.

Detailed information about the contents of the daemon.json file can be found in Daemon configuration fileOpens in a new tab in the Docker documentation; see also Configure and troubleshoot the Docker daemonOpens in a new tab.

Weave Network IP Address Range Conflict

By default, the Weave network uses IP address range 10.32.0.0/12. If this conflicts with an existing network, you may see an error such as the following in log file installWeave.log:

Network 10.32.0.0/12 overlaps with existing route 10.0.0.0/8 on host
ERROR: Default --ipalloc-range 10.32.0.0/12 overlaps with existing route on host.
You must pick another range and set it on all hosts.

This is most likely to occur with provider PreExisting if the machines provided have undergone custom network configuration to support other software or local policies. If disabling or moving the other network is not an option, you can change the Weave configuration instead, using the following procedure:

1. Edit the following file local to the ICM container:

   /ICM/etc/toHost/installWeave.sh
   

   

2. Find the line containing the string weave launch. If you're confident there is no danger of overlap between Weave and the existing network, you can force Weave to continue use the default range by adding the underscored text in the following:

   sudo /usr/local/bin/weave launch --ipalloc-range 10.32.0.0/12 --password $2 
   

   

   You can also simply move Weave to another private network, as follows:

   sudo /usr/local/bin/weave launch --ipalloc-range 172.30.0.0/16 --password $2
   

   

3. Save the file.

4. Reprovision the cluster.

Huge Pages

On certain architectures you may see an error similar to the following in the InterSystems IRIS messages log:

0 Automatically configuring buffers 
1 Insufficient privileges to allocate Huge Pages; nonroot instance requires CAP_IPC_LOCK capability for Huge Pages. 
2 Failed to allocate 1316MB shared memory using Huge Pages. Startup will retry with standard pages. If huge pages 
  are needed for performance, check the OS settings and consider marking them as required with the InterSystems IRIS 
  'memlock' configuration parameter.

This can be remedied by providing the following option to the icm run command:

-options "--cap-add IPC_LOCK"