Skip to main content

Mirrors

Define mirrors that include this instance.

Synopsis

[Mirrors]    Name=a,b,c,d,e,f,g,h,i,j|k,l,m,n,o,p

Description

The [Mirrors] section contains an entry for each mirror connected to the current InterSystems IRIS® data platform instance. The entries are made up of a Name and 14 comma-separated values (an), as follows:

  • Name – Required. Unique name by which you can identify this mirror. An uppercase alphanumeric string with a maximum length of 15 characters.

  • a (GUID) – Required. An internal GUID, unique to this mirror.

  • b (2) – For internal use.

  • c (1) – For internal use.

  • d (Defined Primary) – Used to disable mirror failover, generally for maintenance purposes. Manipulated via the nofailover option when shutting down InterSystems IRIS or the ^MIRROR routine. This contains the mirror name of the member which must be the primary. It is cleared automatically when that node starts up and becomes the primary.

  • e (QOSTimeout) – Quality of Service Timeout: the maximum time, in milliseconds, that a failover member waits for a response from the other failover member before taking action; also applies to the arbiter’s wait for a failover member’s response. The default is 8000ms; typically, deployments on physical (non-virtualized) hosts with a dedicated local network can reduce this setting if a faster response to outages is required. See Configuring the Quality of Service (QoS) Timeout Setting in the “Mirroring” chapter in High Availability Guide for more information on the QoS Timeout setting.

  • f (0) – For internal use.

  • g (UseSSL) – To provide security within a mirror, you can configure its nodes to use SSL/TLS. This provides for both authentication of one node to another, and for encrypted communication between nodes. To use SSL/TLS with a mirror, each member (failover or async) uses a pair of SSL/TLS configurations, %Mirror_Client and %Mirror_Server. These configurations must already exist on each member when SSL/TLS is enabled for the mirror. Instructions for setting up SSL are in the section Creating and Editing SSL/TLS Configurations for a Mirror of the “Using SSL/TLS with InterSystems IRIS” chapter in Security Administration Guide. Values are 0 (no, default) or 1 (yes).

  • h (VirtualAddress) – Specifies a virtual IP address. You can configure a mirror virtual IP address (VIP) so that all external clients (language bindings, ODBC/JDBC/SQL clients, and so on) connect to the mirror through a single address. This virtual IP address is automatically bound to an interface on the current primary member. To use a VIP, which requires that both failover members be on the same subnet. For more information, see the Configuring a Mirror Virtual IP (VIP) section of the chapter “Mirroring” in the High Availability Guide.

  • i (0) – For internal use.

  • j (ArbiterNode) – The network address of the arbiter configured for this mirror. The arbiter is an independent instance hosting an ISCAgent with which the failover members of a mirror maintain continuous contact, providing them with the context needed to safely make failover decisions when they cannot communicate directly.

  • k (ArbiterPort) – The port used by the configured arbiter’s ISCAgent process (2188 by default). Appears in the same space as j, separated by a vertical bar.

  • l (CompressionForFailoverMembers) – Determines whether journal data is compressed before being transmitted from the primary to the backup. Possible values are 0 (System Selected, which optimizes for response time between failover members), 1 (Uncompressed), and 2 (Compressed).

  • m (CompressionForAsyncMembers) – Determines whether journal data is compressed before being transmitted from the primary to async members. Possible values are 0 (System Selected, which optimizes for network utilization), 1 (Uncompressed), and 2 (Compressed).

  • n (AllowParallelDejournaling) – Determines which type of mirror members can run parallel dejournaling updaters. Possible values are 0 (failover and disaster recover members), 1 (failover members only), and 2 (all members).

  • o (CompressionTypeForFailoverMembers) – Determines the compression type for CompressionForFailoverMembers. Possible values are 0 (ZLIB), 1 (ZSTD), and 2 (LZ4).

  • p (CompressionTypeForAsyncMembers) – Determines the compression type for CompressionForAsyncMembers. Possible values are 0 (ZLIB), 1 (ZSTD), and 2 (LZ4).

For more information on Mirroring, see the “Mirroring” chapter in High Availability Guide.

Management Portal

On the Create a Mirror page of the Management Portal (System Administration > Configuration > Mirror Settings > Create a Mirror), enter the requested information. You can edit an existing mirror on the Edit Mirror page, but only from the primary failover member.