#Mirroring

Hi all,

Just wondering if anyone has any experience with licensing in an HA mirroring environment. We have mirror setup with 2 DB servers (Primary and Backup), and a separate Arbiter using ISCAgent. We currently don't have a license server setup so users using our web app get interruptions and have to log in again if failover occurs. 

We have also see some spurious licensing issues when failover occurs and users are logging back in. So we were wondering if using a separate License server (possibly hosted on the Arbiter machine) would help alleviate these licensing issues?

I am attempting to failover my TEST environment to the Backup, and I keep getting an error stating that 

06/01/25-18:47:54:516 (11864) 1 [Utility.Event] Primary startup failed, failed to read header of /archive/journal/MIRROR-IRISTEST-20250513.007 (file #63653)

however, when I go to /archive/journal/, I am not finding any record of MIRROR-IRISTEST-20250513.007 (file #63653)

to get out of this error message I have to restart what was the Primary and restart the Backup to get it back into a state that we can use it.

Hello,

We had a weird behavior of task manager in mirror async backup-failover pair:

1. server 1 was primary, server 2 backup for over a month, as there was no automatic failover (switch) both had IRIS up for over a month
2. We manually switched making server 2 primary
3. The tasks that had this issue were set to "run on Primary only"
4. Task manager started to execute tasks every minute: we noticed that "Next scheduled time" is always calculated in past date, and progressing by the task interval (e.g. a task that supposed to run every hour will have "Next scheduled time" in the past e.g.

Is it possible to use one IIS server to configure Webgateway and external Webserver for management portal when implementing synchronous mirroring with VIP  i.e Is it necessary to have two mirror servers(primary and Backup) , one Arbiter server, one Webserver for Webgateway and a sperate webserver for management portal? 

If anyone can please point to any documentation on Mirroring with Webgateway and external webserver for management  portal will be really helpful. 

Thank you for your help

Hi Experts Can you advise how to setup a nic for VIP ?

Can you confirm that using this command is the correct

ip addr add *.*.*.*/2 dev nic?

then configure the VirtualAddressInterface in iris.cpf

restart and end enable in the smp?

thank you in advance

I want to use ^Mirror routine to configure mirroring. Can someone please tell what classes and methods I need to use with syntax for configuring the mirroring please OR please point me to any tutorial where ^Mirror routine is used to configure mirror.

The SYS.Mirror CatchupDB() method requires a System File Number/Inode value as a parameter.   I have not yet found a suitable internal method to get this value.  Is anyone aware of a utility method that would do this?   I do know I can get this value with a small amount of Python or by calling out to the OS.  However I wanted to stick with pure Objectscript in this project if possible.  

Failing in this I will use embedded python to run the line or two of Python needed to get this value.

Thank you for any hints

ISCAgent is automatically installed with Cache, runs as a service and can be configured to
start with the system. This is fine – but the complication comes when this is on VCS clusters with
Mirroring on. When installing a Single Instance of Cache in a Cluster, point number 2. Says “Create
a link from /usr/local/etc/cachesys to the shared disk. This forces the Caché registry and all
supporting files to be stored on the shared disk resource you have configured as part of the
service group.

Hi! I am planning to move my Arbiter from a Unix server to a container(again on linux). To do this, I need the ISCAgent tar.gz file to configure Arbiter for our mirrored servers. I have tried searching for it on the Intersystems help forums but couldn't find it. Is it possible for someone to redirect me to the correct website to download it?

Thank you in advance!!

I had a question about using ZSTART, ZSTOP, and ZMIRROR.

• If we use them and it is not correct, does it mess up with any of the existing functionality?
• So, if I create a ZSTART with a simple command of starting the %JDBC Server will that mess up anything existing in the Startup sequence?
• Is ZSTART, ZSTOP, and ZMIRROR just an extension of the existing functionality, or does it alter how the built in functionality runs?
• Should we tread lightly in the use of them?

Has anyone noticed that when IRIS is forced down that the EnsLib.JavaGateway.Services do not properly shut down and release the ports? While we can write a shell script to kill the processes at the OS level, I was wondering if anyone experienced this issue.

We are working on our Mirroring setup/failover and had the team testing forcing the Primary down to make the Backup to become the Primary Server. When this happened and we failed back, IRIS could not restart the JavaGateway.Services because the ports were still in use.

Hello, we deploy IRIScluster using IKO on Red Hat OpenShift deployed in AWS. For DR, we have another AWS region on stand by. We do daily backups. I run a standalone IRIS in the second region. I want to add it as async member to the mirror to have some essential data available in the standby region. Is this possible?

We recently went through an Audit of our Security Policies and Procedures when it comes to IRIS. As a result of that Audit, we need to make adjustments to the way that Security is setup within IRIS. I have already done my changes on our TEST and DEVELOPMENT environments, but now I am trying to plan out how do we make these changes in Production.

These changes include moving away from the PWS, setting up Apache/Web Gateway, moving to LDAP instead of using Delegated Authentication, updating Web Applications, updating Resources, updating Services, etc.

I am trying to work on a ZMIRROR that will execute a shell script to failover our VIP at the hardware level when NotifyBecomePrimary occurs.

ZMIRROR ; Custom logic for specific mirroring events
 q
 ;
NotifyBecomePrimary() PUBLIC {
 #;This procedure is called as a notification when this system becomes Primary.
 #;It does not return any value.
 #; invoke the command to select this host for running the crontab
 try {
	Set cmd = "/usr/local/sbin/failover-intengtest-vip_SR"
	d $ZF(-100,"/SHELL /LOGCMD /STDOUT=/archive/logs/failover-intengtest-vip.

How can I check the currently installed version number of an ISCAgent running as the Arbiter in a Red Hat instance?

I can check the properties on a Windows system. I doesn't seem to respond to a --version argument in terminal.

It appears to be working correctly, mirroring data etc. but the status on the Primary Cache DB is showing the wrong status for the DR DB.

 re-configured Cache Mirroring BUt  still have the same issue afterwards.

The GUI display remains the same regardless.

MIRROR is the best solution for almost immediate replications to a Failover Server.
The related mechanics are based on Global Journaling.

Globals hold Data and Classes and Routines and more ...
If Mirroring is in place all is in sync. With minimum delays
This is of course  rather useful for code changes in Classes, Routines, ....

To what extent is Embedded Python covered by Mirroring?
Or:
What is required to Synchronize EmbeddedPython like Mirroring. 

Is there any built-in functionality to send out an email or a text message when a mirror member fails?

Hello Everyone,

We currently have CSP application that runs under 2 servers(usually primary), and every month the server reboots for patching SERVER1(primary) in the morning and SERVER2(backup) at night.

Whenever the SERVER1 reboots SERVER2 behaves as primary and when SERVER1 comes back up it will act as backup server.

First Patching:

So, when SERVER1 is down, I need to start httpd service for SERVER2 and stop httpd service for SERVER1 (which is now backup server).

I tried using the code below in terminal to start httpd service for SERVER2 with no success.

We are noticing some issues with the communication between our Arbiter and our servers. Looking at the following documentation to limit connections, and logging...https://docs.intersystems.com/irislatest/csp/docbook/DocBook.UI.Page.cls?KEY=GHA_mirror_set_config#GHA_mirror_set_agent_port

if I am configuring the ISCAgent on the arbiter, would we set 

application_server.interface_address=<ip_address>

to each IRIS server? Or does this mean to give it a specific NIC IP Address to use for communication?

Has anyone firstly got VIP working for mirroring in Azure?  We are pretty sure that this won't work but I wanted to verify it.

Has anyone used the Azure Load balancer to act as a Virtual IP and if so was a application gateway required.

Interested to know your experiences in getting this working.

I'm trying to create a simple mirror with two Cachés 2016.2.1.803 Instances,

but after i create the mirror with the primary and try to connect the fallouver server, i receive the following message:

ERRO #2071: Erro ao recuperar informações do conjunto espelho para 'BPLUS'. Erro: Connection failed: Unexpected error: <READ>SSLServer+191^MIRRORCTL

i'm not using ssl on this configuration, tried with arbiter and without, same effect.

Tried with Caché 2018.1 and Caché 2016.2.1, same problem.

Some tips?

Best,

Hello everyone!
Maybe someone will tell me what could be the reason for such messages in the message.log file
05/03/23-06:46:27:155 (6584) 0 [Utility.Event] [SYSTEM MONITOR] Mirror state: Member type = Failover, Status = Transition
05/03/23-06:46:27:350 (1620) 1 [Utility.Event] Failed InstanceLookup (agent probably not running): instance not found
05/03/23-06:46:27:351 (1620) 2 [Utility.Event] Failed to become either Primary or Backup at startup
05/03/23-06:46:27:725 (1620) 1 [Utility.Event] Failed InstanceLookup (agent probably not running): instance not found

ISCAgent service is running.

I am working on setting up our Failover techniques as we move to a Mirror Environment with a Arbiter, 2 Failover Nodes, and a Async (DR) Node. There are some system commands that I would like to call when the Mirror moves, and I am working on a ZMIRROR routine for that, but I also wanted to create an additional step if we wanted to manually shutdown and for the Mirror to move. So I was looking at using ZSTOP to call a couple of different items while shutting down, while the documentation has an example a couple of questions come to mind about using ZSTOP.

I am new to setting up a mirror environment....

We will have a Arbiter, Two Failover members (A,B), and a Async (DR) member (C). I have the two failover members in sync and are configured for Arbiter Control.

My question is about the Async member, when I initially set it up I pointed it to the mirror on the primary node A.

Is that correct?

What happens to the Async member (C) if we fail over the mirror to the secondary member B?

Hi,

Question about ZMIRROR routine.

I analyze a problem with the label NotifyBecomePrimary. It seems not performed after a switch.

After installing ZMIRROR routine in %SYS, is a restart required?
If It's required, It could be explain my problem.

Thank you.

Does anyone have experience with installing the Arbiter Container using Podman instead of Docker in a Red Hat environment? I was able to pull down the docker image, but unsure what are the next steps as I am confused on how to start the container using Podman and ensure the parameters are set appropriately? Does anyone have the steps that I should take? Should I go through the WRC? Does the WRC have experience using Podman?

Or should I just install the ISC Agent instead of using the Container?

Please and thanks,

Scott Roth

I've been trying for a while to come up with a set of tools to monitor the health of a mirror set and email a report nightly on the status of the mirror, or flag issues in real time.
Making sure that all the databases are caught up, that all the mirror members are online. 

I've tried a number of methods I've found to try to access the state of the mirror and mostly found they're internal or unsupported routes, (that when questioning WRC have swiftly been removed from the online documentation.).

Hi All,

Our mirrored HealthShare environment has failed over a few times recently due to underlying infrastructure issues (that are being worked on and resolved).

In the HealthShare logs we are seeing:

10/06/22-00:54:35:925 (4736) 1 Journal Daemon has been inactive with I/O pending for 10 seconds:
gjrnoff=524741316,iocomplete=523852600,filecnt=1011,fail=0
10/06/22-00:54:55:086 (4736) 3 CP: Pausing users because Journal Daemon has not shown
    signs of activity for 30 seconds.