#Mirroring

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Mirroring is an InterSystems technology for High Availability, Disaster Recovery and Database Backup and OLAP solutions.

Documentation.

Question William Proctor · Mar 23, 2017

Hello,  Thanks in advance for all replies.  I have been practicing setting up mirroring between two development servers in preparation for mirroring our production server in a few weeks.  I started by setting the servers up with minimum security which worked easily, then I set it up in lock down mode again without any issues.  Now I am setting it up in lockdown mode with encryption and this one is testing me.  I have everything setup but my async dr member cannot connect to the primary.

from cconsole.log

3/23/17-10:09:39:851 (3124) 0 [SYSTEM MONITOR] Mirror status changed.

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Article Pete Greskoff · Jan 10, 2017 9m read

NB. Please be advised that PKI is not intended to produce certificates for secure production systems. You should make alternate arrangements to create certificates for your productions.
NB. PKI is deprecated as of IRIS 2024.1: documentation and announcement.

In this post, I am going to detail how to set up a mirror using SSL, including generating the certificates and keys via the Public Key Infrastructure built in to Caché. The goal of this is to take you from new installations to a working mirror with SSL, including a primary, backup, and DR async member, along with a mirrored database.

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Question Thomas Kotze · Jan 31, 2017

Hi,

Initially when setting up a cache instance one creates or imports the user/ resources roles etc .

After the Mirror has been activated you can add users, resources etc. But when trying to add new SQL Table privileges to a namespace where the databases are mirrored it seems that you are not able to , Getting error: 

ERROR #5002: Cache error: <DIRECTORY>SQLUserPrivsExecute+13^%SYS.SQLSEC

SOURCE ELEMENT: %CSP.UI.Component.SQLTables (SQLTables)
How do you maintain these privileges?

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Question Rich Taylor · Aug 18, 2016

I have setup an async reporting mirror member with Read only access.  My problem is that if I try to do any sql reporting against that data I am getting errors.  I am sure that this is because the DB is read only, but I had assumed that setting up a reporting mirror would handle this.

I there a setting or mapping  I am missing?

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Article Bob Binstock · Sep 7, 2016 6m read

Mirror Outage Procedures

Caché mirroring is a reliable, inexpensive and easy to implement high availability and disaster recovery solution for Caché and Ensemble-based applications. This article provides an overview of recommended procedures for dealing with a variety of planned and unplanned mirror outage scenarios. (For detailed information about mirroring and a wide range of mirror-related procedures, see Mirroring 101.)

A Caché mirror typically consists of two Caché instances on physically independent hosts, called failover members

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Question Joan Cruz · Aug 2, 2016

Hi all,

I'm using $ZUTIL(49) to get information of the databases I want to add to a mirror. This information is passed to  ##class(SYS.Mirror).CatchupDB(plstPathDatabases)  in order to Catchup all databases addes to a Mirror.

I know that ZUTIL is deprecated and I'd like to know what function or functions I have to use in order to get all necessary information for CatchupDB.

Thanks a lot

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Article Mark Bolinsky · Jul 1, 2016 17m read

++Update: August 2, 2018

This article provides a reference architecture as a sample for providing robust performing and highly available applications based on InterSystems Technologies that are applicable to Caché, Ensemble, HealthShare, TrakCare, and associated embedded technologies such as DeepSee, iKnow, Zen and Zen Mojo.

Azure has two different deployment models for creating and working with resources: Azure Classic and Azure Resource Manager. The information detailed in this article is based on the Azure Resource Manager model (ARM).

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Question Ray Fucillo · Jun 6, 2016

Mirroring provides an admin capability to Stop Mirroring on this member, which causes a non-primary member to temporarily disconnect from the primary, stop dejournaling, etc.  While most system administrators may never need or use this function, some employ it for certain kinds of maintenance or other special cases.

The intent is that the administrator uses the Start Mirroring function when they wish the member to reconnect. However, today mirroring also implicitly restarts (reconnects) if the Caché instance restarts.

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Question Mikhail Khomenko · May 12, 2016

Good day, Cache developers and users!

At first, sorry for my bad English -)  I have a little question.

As I know, we can add database to mirror only on Primary Failover Node, using SMP or ^MIRROR. And the usual procedure after that is to copy mirrored database to Backup Failover Node and restore it there (by Backup restore or by Activate-Synchronize procedure). This all works fine. But what if I first have copied the database from Primary to Backup and only than added the database to mirror on Primary Failover Node? (human forgetfulness).

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Article Mark Bolinsky · Apr 7, 2016 1m read

Presenter: Mark Bolinsky
Task: Provide failover for distributed systems without using a VIP
Approach: Demonstrate using InterSystems’ database mirroring with external traffic managers such as F5 LTM/GTM
 

With distributed environments and even public cloud environments, the use of a VIP sometimes is not desirable or even possible given network topology or deployment. The session will demonstrate integrating database mirroring with external traffic managers such F5 LTM/GTM using API based triggers in InterSystems products to interface with the F5 appliances. This not only presents automated redirection for the local mirror members, but also provided automated client redirection to asynchronous DR mirror members. 

Content related to this session, including slides, video and additional learning content can be found here.

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Article Ray Fucillo · Apr 7, 2016 1m read

Presenter: Ray Fucillo
Task: Provide high availability (HA) and disaster recovery (DR) in diverse architectures that demand high performance, including replication over long distances
Approach: Give examples of mirror architectures in disparate environments, including geographically separated systems. Discuss performance considerations and advances in InterSystems’ mirroring technology
 

In this session you will learn about deploying Mirroring to provide HA and DR in diverse architectures that demand high performance and throughput. Challenges and solutions to achieving high throughput will be covered along with mirror architectures that involve long distances and disparate environments.

Content related to this session, including slides, video and additional learning content can be found here.

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Article John Murray · Mar 17, 2016 2m read

Here are a few tips that might be useful to people who are running applications in an environment that's configured to use InterSystems mirroring.

  • If you configure an ECP connection to a Caché instance that is a mirror member databases then the ECP connection should also have mirroring enabled (tick the mirroring box when defining the connection). More details here. You may also need to increase the number of ECP connections each end accepts, to cater for the way both members of a mirror pair get involved in ECP negotiation.
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Question Steve Pisani · Mar 8, 2016

Hi,

Can a Cache Mirror be  used in the cloud ? (ie stand up a Primary and Backup member instances in a High Availability Cache Mirroring configuration) 

I'm investigating the validity of this configuration, because I was of the understanding that this may not possible due to these cloud servers not (typically) having fixed ip addresses, which interferes with the Virtual IP settings for the mirror set.

Is this correct, and if there are workarounds (like Load Balancing ?) can I have details on how this should be configured ?

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Article Developer Community Admin · Oct 21, 2015 3m read

Providing a reliable infrastructure for rapid, unattended, automated failover

Technology Overview

Traditional availability and replication solutions often require substantial capital investments in infrastructure, deployment, configuration, software licensing, and planning. Caché Database Mirroring (Mirroring) is designed to provide an economical solution for rapid, reliable, robust, automatic failover between two Caché systems, making mirroring the ideal automatic failover high-availability solution for the enterprise.

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Article Developer Community Admin · Oct 21, 2015 2m read

Providing a reliable infrastructure for rapid, unattended, automated failover

Technology Overview

Traditional availability and replication solutions often require substantial capital investments in infrastructure, deployment, configuration, software licensing, and planning. Caché Database Mirroring (Mirroring) is designed to provide an economical solution for rapid, reliable, robust, automatic failover between two Caché systems, making mirroring the ideal automatic failover high-availability solution for the enterprise.

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