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Installation Guide
Upgrading InterSystems IRIS
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This chapter is intended for customers who are upgrading from InterSystems 2018.1.0 and later. Topics in this chapter include:
Important:
Before upgrading, review the following documents:
Caution:
Prior to beginning an upgrade of an InterSyetems IRIS instance, it is essential that the instance be shut down cleanly. To verify that the shutdown was clean, examine the cconsole.log file after the shutdown finishes. If the log contains entries similar to the following, then the shutdown was clean:
...
05/03/18-14:24:13:234 (5204) 0 Journal restore not required at next startup
05/03/18-14:24:13:234 (5204) 0 Transaction rollback not required at next startup
...
If these entries are not present, the instance did not shut down cleanly. Please contact the InterSystems Worldwide Response Center before proceeding with the upgrade.
Upgrading to a Maintenance Release
Most of the information in this chapter applies to upgrading InterSystems IRIS to a new major version. If you are upgrading to a maintenance release of the installed version of InterSystems IRIS, review the following:
Performing Upgrade Tasks
The following upgrade tasks are necessary regardless of the platform on which you are upgrading and running InterSystems IRIS. Perform these tasks before you run the InterSystems IRIS installation procedures:
  1. Obtain an updated license key — See the “Managing InterSystems IRIS Licensing” chapter of the System Administration Guide for more information.
  2. Back up the system — before upgrading, InterSystems recommends that you run a complete backup of your system. Use your customary full operating system backup procedures.
  3. Check system integrity — run a system integrity check on existing directories to ensure there is no corruption in any of the databases.
  4. Save custom classes, routines and globals — to prevent your own classes, routines and globals in the %SYS namespace from being affected by the upgrade installation, ensure that they have names that begin with “Z”, “z”, “%Z”, or “%z”. All .int and .obj routines (except for Z*, z*, %Z*, and %z*) are deleted from the %SYS namespace when upgrading.
    On an upgrade, the IRISLIB, IRISTEMP, and IRIS databases are completely replaced.
    Any .mac or .inc routines are not affected during the upgrade.
  5. Save user files — to ensure that your user files are not deleted or replaced during upgrades, save them in the install-dir\Mgr\User directory, which is the only directory that is not subject to modification during upgrades (that is, except for the install-dir\Mgr\User directory, any files and directories in the InterSystems IRIS install directory may be deleted or replaced during upgrades).
  6. Review encryption settings — If you are upgrading using an .rpm file, you must disable database encryption before upgrading and reenable it when the upgrade is complete.
In addition, there are other tasks that may be necessary depending on your environment and the components as described the following sections:
Upgrading Mirroring with Minimum Downtime
This section provides instructions for upgrading InterSystems IRIS instances, an application, or both on the members of an InterSystems IRIS mirror.
As noted in the Mirroring chapter of the InterSystems IRIS High Availability Guide, all failover and DR async members of a mirror must be of the same InterSystems IRIS version, and can differ only for the duration of an upgrade. Once an upgraded member becomes primary, you cannot make use of the other failover member and any DR async members (and in particular cannot allow them to become the primary) until the upgrade is completed.
Mirroring does not require reporting async members to be of the same InterSystems IRIS version as the failover members, although application functionality may require it; see the “Supported Version Interoperability” chapter of the online InterSystems Supported Platforms document for this release for information about reporting async version requirements.
There are four mirror upgrade procedures, as follows. The first three procedures are designed to let you perform the upgrade you need with the shortest possible application downtime; they differ to accommodate different upgrade circumstances. The last, which is a bit simpler, can be used for any type of upgrade when minimizing downtime is not a priority.
Choosing Mirror Upgrade Procedure provides an overview of the factors that determine which procedure you should use. Your circumstances may call for additional steps and details in a given procedure. If you are unsure which procedure is appropriate for you or whether a particular procedure is appropriate as stated, please contact the InterSystems Worldwide Response Center (WRC).
To avoid repetition, Minimum Downtime Upgrade Terms defines the terms that are used in multiple procedures.
Important:
On Linux systems supporting systemd, although it is possible to use either systemctl commands or the /etc/init.d/ISCAgent script to manage the ISCAgent, you must choose one method and use it exclusively; the ISCAgent should always be stopped using the method with which it was started (see Starting the ISCAgent on Linux Systems in the “Mirroring” chapter of the InterSystems High Availability Guide).
When you upgrade InterSystems IRIS on such a Linux system, a running ISCAgent is automatically restarted using systemd. If you are using the /etc/init.d/ISCAgent script to manage the ISCAgent, stop the agent before performing the upgrade so that it is not automatically restarted, then restart it using the script after the upgrade.
Choosing Mirror Upgrade Procedure
There are two primary factors to consider in choosing the procedure appropriate for your mirror upgrade:
Whenever you upgrade to a maintenance release and are not making any application upgrades, you do not have to consider the second question; you can always use the simple Maintenance Release Upgrade procedure, which renders the mirror unavailable only for the time it takes to execute a planned failover.
However, when you upgrade from one major InterSystems IRIS version to another, perform application upgrades, or both, there is the possibility that your upgrade will involve changes to mirrored databases. Such changes must occur on the functioning primary failover member as part of the upgrade procedure, while application access is disabled. As a result, the upgrade requires more downtime than if you are not making any mirrored database changes. (The changes will then be replicated by the mirror on the backup and any async members.)
Important:
Following a major upgrade, InterSystems recommends that you recompile all classes in all application namespaces on the instance and some routines must also be recompiled (see Upgrade Specifics in the chapter General Upgrade Information in the InterSystems IRIS Release Notes and Upgrade Checklist). Any application upgrade you perform may require changes to application data. In either of these situations, your upgrade may result in changes to mirrored databases.
If you are upgrading to a major release, are performing application upgrades, or both, you must determine whether any of the following conditions apply:
If your major upgrade and/or application upgrade involves any of these conditions, use the Major Upgrade (Mirrored Database Changes) procedure, which renders the mirror unavailable only for the time it takes to execute a planned failover and make the required mirrored database changes.
If your upgrade does not involve any of the listed mirrored database changes, consider the Major Upgrade (No Mirrored Database Changes) procedure, which renders the mirror unavailable only for the time it takes to execute a planned failover.
If you have a significant planned maintenance window and minimizing mirror downtime is not a major concern, you may choose to use the simpler Major Upgrade with Planned Downtime procedure instead.
In the case of major upgrades, the general sequence of each procedure applies to upgrades of the mirror’s InterSystems IRIS instances, application code, or both; adapt individual steps depending on what you are upgrading.
Adding Mirror Members During an Upgrade
If you plan to add members to a mirror, you may want to defer this until you plan to perform one of the upgrades described in this section and add members of the new version during the upgrade, so that you will not have to upgrade them later. You can always add members of a newer version to a mirror during an upgrade, provided you immediately continue with and complete the upgrade as described, with one restriction: once a member of the newer version becomes primary, it must remain primary until all other members have been upgraded.
Adding new members during an upgrade can be very helpful when migrating a mirror to new hardware. Rather than upgrading one of the failover members before failing over to it, you can install a new instance of the new version on the target system, add it to the mirror as a DR async member, promote it to backup and then fail over to it, thus migrating the mirror primary to the new system. By repeating this technique you can then migrate the remaining failover member. The procedures in this section include steps for adding a new backup of the new version as an alternative to upgrading the existing backup, to illustrate this approach.
Minimum Downtime Upgrade Terms
In the procedures in this section, the following terms are used:
Upgrading to InterSystems IRIS Maintenance Release
If you are upgrading to an InterSystems IRIS maintenance release rather than a new major InterSystems IRIS version and are not making any application changes, use the following procedure, which renders the mirror unavailable only for the time required to execute a planned failover:
  1. To prevent failover from occurring until the backup is fully upgraded, set no failover.
  2. Perform one of the following two operations:
  3. Ensure that the backup (B or C) has become active by viewing the Mirror Monitor.
  4. Clear no failover.
  5. Perform a graceful shutdown of the primary (A). The mirror fails over and the backup (B or C) takes over as primary.
  6. Upgrade system A with the new version of InterSystems IRIS. System A becomes backup.
  7. If system C became primary and system B was demoted to DR async, upgrade system B.
Upgrading to Major InterSystems IRIS Version with Mirrored Database Changes
If you are upgrading to a new major InterSystems IRIS version and/or performing an application upgrade and have determined that changes to mirrored databases are required (as described in Choosing a Mirror Upgrade Procedure), use the following procedure, which renders the mirror unavailable only for the time it takes to execute a planned failover and make the required mirrored database changes:
  1. To prevent failover from occurring until the backup is fully upgraded, set no failover.
  2. Perform one of the following two operations:
  3. Ensure that the backup (B or C) has become active by viewing the Mirror Monitor.
  4. Disallow new user access to the mirror using established practices at your site. Additionally, you must disable any application jobs that would normally start on system B when it becomes primary.
  5. Clear no failover.
  6. Perform a graceful shutdown of the primary (A). The mirror fails over and the backup (B or C) takes over as primary
  7. Upgrade mirrored classes and routines on the new primary (B or C). If an application upgrade requires further changes to mirrored databases, make these changes.
  8. Restore user access to the mirror.
  9. To prevent system A from taking over as primary until fully upgraded, set no failover
  10. Upgrade system A with the new version of InterSystems IRIS. System A becomes backup.
  11. Upgrade non-mirrored classes and routines on system A, if any.
  12. Clear no failover.
  13. If system C became primary and system B was demoted to DR async, upgrade system B and upgrade non-mirrored classes and routines on system B, if any.
Upgrading to Major InterSystems IRIS Version with No Mirrored Database Changes
If you are upgrading to a new major InterSystems IRIS version and/or performing an application upgrade and have determined that changes to mirrored databases are not required (as described in Choosing a Mirror Upgrade Procedure), you may be able to use the following procedure.
This procedure is simplest for static applications where separate non-mirrored routine databases are always maintained. It can, however, be used even if the separate routine databases are normally mirrored by removing these databases from the mirror for the duration of the upgrade.
Important:
If the routine databases are normally mirrored, ensure that they do not contain any application data before removing them from the mirror.
This procedure cannot be used with normally mirrored routine databases if ECP application servers connect to the mirror.
  1. Enact a code freeze and application configuration freeze to disallow application changes during the upgrade, using established procedures at your site, to ensure that routine databases are not modified during the upgrade.
  2. To prevent failover from occurring until the backup is fully upgraded, set no failover.
  3. Perform one of the following two operations:
  4. Clear no failover.
  5. Perform a graceful shutdown of the primary (A). The mirror fails over and the backup (B or C) takes over as primary.
  6. To prevent system A from taking over as primary until fully upgraded, set no failover,
  7. Upgrade system A with the new version of InterSystems IRIS. System A becomes backup.
  8. Upgrade any non-mirrored classes and routines on system A.
  9. If system C became primary and system B was demoted to DR async, upgrade system B and upgrade non-mirrored classes and routines on system B, if any.
  10. For any mirrored routine databases that you removed from the mirror on backup (B or C) before it became the new primary, do the following:
    1. Remove the routine databases from the mirror on system A.
    2. Add the databases to the mirror on the new primary (B or C), then back them up and restore them on the backup (A) and DR async (B, if C is the primary), using the procedures for adding an existing database to a mirror provided in Adding Databases to a Mirror in the “Mirror” chapter of the InterSystems IRIS High Availability Guide. Retain these backups, as they represent the first backups of newly-added mirrored databases; older backups made prior to the upgrade cannot be used to restore these databases in the event of disaster.
  11. Clear no failover.
Upgrading to Major InterSystems IRIS Version with Planned Downtime
If you are upgrading to a new major InterSystems IRIS version and/or performing an application upgrade and have a significant planned maintenance window that obviates the need to minimize mirror downtime, you may prefer to use the following simpler procedure, regardless of whether changes to mirrored databases on the primary are required:
  1. Disallow all user access to the mirror using established practices at your site. Additionally, you must disable any application jobs that would normally start on instance startup.
  2. Perform a graceful shutdown of the backup (B).
  3. Perform a graceful shutdown of the primary (A).
  4. Upgrade system A with the new version of InterSystems IRIS. System A becomes primary.
  5. Upgrade mirrored classes and routines on system A. If an application upgrade requires further changes to mirrored databases, make these changes.
  6. Upgrade non-mirrored classes and routines on system A, if any.
  7. Perform one of the following two operations:
  8. If system C became primary and system B was demoted to DR async, upgrade system B and upgrade non-mirrored classes and routines on system B, if any.
  9. Restore user access to the mirror.
Upgrading ECP Configurations
In general, ECP application servers should be upgraded before the data servers they connect to. Application servers must have either local routines databases to recompile following upgrade or access to “precompiled” routines database (previously recompiled on a separate system running the target InterSystems IRIS version) on the data server.
Downtime can be minimized using rolling upgrades with users connecting to both upgraded and unupgraded application servers as well as the database server if one of the following is true:
If the new application code can work against old data, but can generate new data structures not understood by the old code, follow this procedure:
  1. Upgrade the application servers on a rolling basis, but do not allow users to connect to an application server once it is upgraded. (Application server capacity will be gradually reduced.)
  2. When enough application servers have been upgraded, restore user access to the upgraded application servers and end all user connections to the remaining (not upgraded) application servers and the data server (if need be), ensuring that users have no access to these systems until you enable it.
  3. Upgrade the remaining application servers, restoring user access to each application server after it is upgraded.
  4. Upgrade the data server and restore user access as needed. (Upgrading the data server will cause a pause in application activity, the length of which will depend on the amount of downtime involved in the upgrade.)
If you have questions or concerns about how to upgrade your ECP configuration, please contact InterSystems Worldwide Customer Support (WRC).
Post-installation Upgrade Tasks
The post-installation tasks required depend on whether you have upgraded to a new major version of InterSystems IRIS or to a maintenance release of the installed version.
Major Version Post-Installation Tasks
After upgrading InterSystems IRIS to a new major version, you must perform the following tasks (if you have not already done so as part of one of the previous procedures in this chapter):
The following tasks may be necessary depending on your environment and the components you use:
Maintenance Release Post-Installation Tasks
After upgrading to a maintenance release of the installed version of InterSystems IRIS you are not required to recompile any classes or routines. However, if you choose to recompile, it is important to follow the guidance provided in Upgrade Specifics in the chapter General Upgrade Information in the InterSystems IRIS Release Notes and Upgrade Checklist.
Typically, no changes to external files or clients are required following a maintenance release upgrade.


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Content Date/Time: 2019-02-18 01:15:52