Using Multiple Instances of Caché

You can install and run multiple instances of Caché on a single host system. Each instance is a unique, independent Caché environment. This chapter addresses the following topics:

Caché Instances

There are many ways to connect to a Caché instance. Two of the most common are through the Caché Launcher (only on Windows platforms) and from the command line of the console.

Each Caché instance installed on a Windows machine has its own launcher. All of the launcher utility functions operate within the context of the instance associated with that launcher.

As you install each instance of Caché, you give it an instance name. To perform command-line procedures on a particular instance of Caché, use this name. You can start, stop, and maintain each of these instances independently. The following table shows the most common commands to manipulate Caché instances.

Control Commands

Action desired	Caché command
Starting a Caché instance	ccontrol start instname
Connecting to a Caché instance	csession instname
Stopping a Caché instance	ccontrol stop instname

These commands are described in detail in Connecting to a Caché Instance (csession) and Controlling Caché Instances (ccontrol).

From the Caché Launcher, you can also control multiple remote Caché environments. Caché allows you to create and edit all Caché data on remote systems. This includes, but is not limited to, running remote backups, editing remote instances, and creating and compiling remote objects and routines. See the chapter “Connecting to Remote Servers” in this guide for more detailed information.

Note:

On Windows platforms, you can also start, stop, and restart a Caché instance by using the Windows Services administrative tool to start, stop, and restart the Caché Controller service for the instance. However, you cannot use this method to start an instance configured for startup with interactive encryption key activation (see Configuring Startup with Interactive Key Activation in the “Managed Key Encryption” chapter of the Caché Security Administration Guide) because it does not allow you to enter the required credentials.

On UNIX® platforms, when a Caché instance is stopped, restarted, or forced down, the instance will wait for all processes to detach from shared memory for a maximum of 30 seconds. After 30 seconds, the instance will close. If there are still processes attached to the shared memory after the instance has closed, restarting the instance will fail.

Connecting to a Caché Instance

Once you have started Caché, you can log into Caché on the command line using the csession command, as follows:

csession <instname> [arguments]

where instname is the name of the instance that you are managing, and [arguments] indicates one or more of the optional arguments described in the following table. On a Windows system, you must execute the command from its location, the install-dir\bin directory of a Caché instance, or include the full path in the command, for example:

C:\InterSystems\Cache27\bin\csession Cache33

Note:

As shown in the preceding example, the instance name you specify can be different from the instance of the csession binary you are executing, but is always required, even if they are the same.

Caché csession Command and Arguments

Command	Description
csession instname -B	Provides system administrator emergency login. Note: To execute an emergency startup on Windows, you must open the Command Prompt using the Run as Administrator option. See also Emergency Access in the “System Management and Security” chapter of the Caché Security Administration Guide for information about starting and logging into Caché in emergency access mode.
csession instname -U namespace	Specifies the login namespace. Note: -U has no effect if you are starting Caché with a user account whose Startup Namespace is specified (see Properties of Users in the “Users” chapter of the Caché Security Administration Guide).
csession instname -b partition_size	Specifies the maximum partition size (in KB) for the process.
csession instname "[label[+offset]]^routine"	Specifies the name of an ObjectScript program to run in user mode. In addition to the specified formats, you can pass parameter lists consisting of string and/or numeric literals, as well as omitted (void) parameters, as follows: "routine[([parameter-list])]" "[label]^routine[([parameter-list])]" "##CLASS(package.class).method[([parameter-list])]" where, for example, parameter-list is specified in the form "string literal",,-+-000123.45600E+07, and omitted parameters are passed to the target as $Data(parameter)=0. Note: Whitespace and shell meta characters must be quoted in an operating-system dependent form.

To use the csession command or the ccontrol command (see Controlling Caché Instances) on a remote server, use csession or Terminal, or a remote connection through Terminal or Telnet/ssh client.

Controlling Caché Instances

You can control an instance of Caché using the ccontrol command. The ccontrol command supports a number of functions and has the following syntax:

ccontrol <function> <instname> [arguments]

where instname is the instance name that you chose during the installation.

Note:

To display the most current help file for running the ccontrol command, invoke ccontrol help. On Windows, run the command from the install-dir\Bin directory (or include the full path with the command):

C:\InterSystems\Cache27\bin>ccontrol help

The ccontrol help command displays the CcontrolHelp.html file in your browser; the file is in the install-dir\Help directory.

The optional arguments (indicated by [arguments]) are:

quietly — non-interactive with minimal dialog
nostu — do not run the startup routine (^STU)
help — print the help message and exit
restart — start Caché after a successful shutdown (for stop function only and not available on Microsoft Windows platforms)

To use the ccontrol command or the csession command (see Connecting to a Caché Instance) on a remote server, use a Telnet or ssh client or the Terminal.

The following table displays some common uses of the ccontrol command.

Important:

The ccontrol command has other platform-specific functions, which can be displayed with the help function; functions that are internal to InterSystems do not appear in the help display.

Caché ccontrol Command and Functions

Command	Description
ccontrol start instname [args]	Starts instance instname. Note: You may be prompted to start in “Emergency Mode;” if so, see Emergency Access in the “System Management and Security” chapter of the Caché Security Administration Guide for more information.
ccontrol start instname [full pathname of .cpf file]	Starts Caché instance instname, optionally using the specified name.cpf file. If a name.cpf file is not specified, the Caché instance uses the cache.cpf file.
ccontrol start instname nostu	On all platforms except Windows, starts the specified instance without running ^STU.
ccontrol startnostu instname	On Windows, starts the specified instance without running ^STU.
ccontrol stop instname [args]	Shuts down an instance.
ccontrol stopnoshut instname 4	Shuts down the named instance using INTNOSHUT^SHUTDOWN.
ccontrol stopstart instname	Shuts down and restarts the named instance.
ccontrol force instname	Forces an instance down.
ccontrol list	Lists the following information for all installed instances: Instance name (and installation type) Installation directory Caché version Pathname of Caché parameter (.cpf) file Superserver and webserver port numbers Instance status, as follows running down starting or stopping incomplete start or stop, logins disabled Instance’s system health state, if running (see System Monitor Health State in the “Using the Caché System Monitor” chapter of the Caché Monitoring Guide) (not included on Windows) Mirror member type and status (if a mirror member) (see %SYSTEM.Mirror.GetMemberType()Opens in a new tab and %SYSTEM.Mirror.GetMemberStatus()Opens in a new tab)
ccontrol qlist	Lists essentially the same information for each instance as ccontrol list, plus the JDBC Gateway port, but without labels and all on one line, separated by carets (^), in the following order. You can specify a single instance on the command line to display information for that instance only. Instance name (and installation type) Installation directory Caché version Instance status Pathname of Caché parameter (.cpf) file Superserver, webserver, and JDBC Gateway port numbers Instance’s system health state, if running (not included on Windows) Mirror member type and status (if a mirror member)
ccontrol all 1	Lists the following information for all installed instances, one instance per line: Instance status, as follows <blank> (status unavailable, logins disabled) dn (down or has crashed) up (running) st (starting or stopping) Instance name Caché version Superserver port number Installation directory
ccontrol allw	Lists the same information for each instance as ccontrol all, without wrapping long field values. Lines longer than 80 characters may result.
ccontrol qall	On platforms other than Windows, lists the same information for each instance as ccontrol all, except that long lines are truncated to 78 characters plus a terminating tilde (~);
ccontrol stat instname [args]	Retrieves system statistics. This is the same as the cstat utility (see the appendix “Monitoring Caché Using the cstat Utility” in the C Monitoring Guide). ccontrol stat is not available on Windows, but cstat is.
ccontrol help	Displays most recent information about the ccontrol command.
ccontrol help [start \| stop \| force]	Gives function-specific help for the start, stop, and force functions.
ccontrol rename instname {newname}	Renames the instance (not available on Windows systems).
ccontrol [run \| console \| cterminal] instname	Runs Caché in programmer mode with either no device, the console, or the terminal for $Principal (Windows only).5
ccontrol [run \| console \| cterminal] instname routine	Runs the named Caché routine in application mode with either no device, the console, or the terminal for $Principal. (Windows only).5
ccontrol [run \| console \| cterminal] instname routine namespace3	Runs the named Caché routine in the indicated namespace in application mode with either no device, the console, or the terminal for $Principal. (Windows only).5
ccontrol runw instname routine [namespace3]	Runs the named Caché routine in the specified namespace (if any) in application mode with no input/output device for $Principal (Windows only). When run from a batch script, ccontrol waits for the Caché process to terminate before returning. The exit code from the Caché process is returned by ccontrol.5

Table Notes

1 If you require complete information, such as for parsing or reporting purposes, use ccontrol list.

2 (removed)

3 The namespace argument has no effect if you are starting Caché with a user account whose namespace property contains a value. See the “Users” chapter of the Caché Security Administration Guide for details on maintaining user accounts.

4 Only owner and cacheusr can run SHUTDOWN without csession login.

5 On UNIX®/Linux systems, these tasks are executed using the csession command (see Connecting to a Caché Instance).

Configuring Multiple Caché Instances

You can install and simultaneously run multiple instances of Caché 4.0 and later on a single machine. Install Caché as for a single installation, giving each instance a unique name, a unique installation directory, and a unique port number for the superserver, web server, and Telnet.

The special considerations for multiple instances are:

Each instance must be version 4.0 or later of Caché. For example, Caché 5.1 and 3.2.1 cannot run on the same machine at the same time.
Multiple instances can share the same multiserver key, but if they do, they must use the same license server or set of license servers. Each system running an instance of Caché under the auspices of one or more license servers must have a local copy of the authorizing license key file installed in every instance.
Multiple instances can be networked.
Protection is included against simultaneous database use (that is, each instance must have its own databases and cannot access or modify another instance’s databases).
Each instance must have unique port numbers. See the next section for information on how to Set Port Numbers.

Note:

Please see the Multiple Caché Installation Issues section of the Caché Installation Guide for important facts when installing multiple instances of Caché on the Windows platform.

Set Port Numbers

For a standard, single instance of Caché, the superserver port number is 1972 by default. For multiple instances of Caché 4.0 and later on a single machine, each must have a unique port number. During installation, subsequent instances are assigned the next available port if you choose to set it automatically, or you can manually enter port numbers during the installation. A standard installation sets the following port numbers for your Caché instance as follows:

Superserver port number — 1972 or the first available subsequent number equal to or higher than 56773
Web server port number — 57772 or the first available subsequent number
Telnet port number — 23

You most likely do not need to change the superserver or web server port numbers because of the way the Caché installation assigns them. However, you do need to assign each instance a unique Telnet port number. You can change the superserver port value after installation from the Memory and Startup page (System Administration > Configuration > System Configuration > Memory and Startup) of the Management Portal, and you can change the web server and Telnet port values after installation from the Startup Settings page (System Administration > Configuration > Additional Settings > Startup) and the Telnet Settings page (System Administration > Configuration > Device Settings > Telnet Settings), respectively, of the Management Portal.

Note:

If you frequently use and manage multiple instances of Caché on one machine, verify that each is assigned unique port numbers. The assignment of unique port numbers avoids confusion when using the Caché Launcher tools on multiple instances from one Windows client.