Mirroring

Syndicate content 12 

In this post I show strategies for backing up Caché using External Backup with examples of integrating with snapshot based solutions. The majority of solutions I see today are deployed on Linux on VMware so a lot of the post shows how solutions integrate VMware snapshot technology as examples.

Last comment 16 November 2018
+ 12   1 5
4382

views

+ 12

rating

++ Update: August 1, 2018

The use of the InterSystems Virtual IP (VIP) address built-in to Caché database mirroring has certain limitations. In particular, it can only be used when mirror members reside the same network subnet. When multiple data centers are used, network subnets are not often “stretched” beyond the physical data center due to added network complexity (more detailed discussion here). For similar reasons, Virtual IP is often not usable when the database is hosted in the cloud.

Network traffic management appliances such as load balancers (physical or virtual) can be used to achieve the same level of transparency, presenting a single address to the client applications or devices. The network traffic manager automatically redirects clients to the current mirror primary’s real IP address. The automation is intended to meet the needs of both HA failover and DR promotion following a disaster. 

Last comment 14 June 2018
+ 11   0 7
2367

views

+ 11

rating

++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).

Last comment 8 July 2016
+ 11   0 1
6199

views

+ 11

rating

Mirroring 101

Caché mirroring is a reliable, inexpensive, and easy to implement high availability and disaster recovery solution for Caché and Ensemble-based applications. Mirroring provides automatic failover under a broad range of planned and unplanned outage scenarios, with application recovery time typically limited to seconds. Logical data replication eliminates storage as a single point of failure and a source of data corruption. Upgrades can be executed with little or no downtime.

Last comment 8 December 2018
+ 7   2 10
3187

views

+ 7

rating

Context: 

mirrored configuration with one primary member and one async member (without failover/backup member)

Purpose:

replace the CACHE.DAT of a mirrored database on the primary member.

 Steps to follow:

Last comment 21 October 2016
+ 5   0 0
459

views

+ 5

rating

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.

+ 4   0 1
0

comments

602

views

+ 4

rating

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. I will not go into security recommendations or restricting access to the files. This is meant to just simply get a mirror up and running.

Last comment 29 March 2017
+ 4   0 0
1131

views

+ 4

rating

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 InterSystems IRIS Data Platform. I did a similar post in the past for Caché, so feel free to check that out here if you are not running InterSystems IRIS. Much like the original, 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. I will not go into security recommendations or restricting access to the files. This is meant to just simply get a mirror up and running. Example screenshots are taken on a 2018.1.1 version of IRIS, so yours may look slightly different.

+ 4   1 1
0

comments

226

views

+ 4

rating

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.

Last answer 7 June 2016 Last comment 7 June 2016
+ 2   0 2
225

views

+ 2

rating

Hi Community!

Please find the Developer Community video of the week on the InterSystems Developers YouTube Channel

Upgrades - Minimizing Business Disruption

 

Last comment 20 July 2017
+ 1   1 3
145

views

+ 1

rating

Good day!
Is there an opportunity to debug the ISCAgent behaviour (in Linux)? ISCAgent uses /etc/iscagent/iscagent.conf as configuration file, but in docs I've found a description only for two parameters (port number and interface - http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=...). Other parameters I can see by running /usr/local/etc/cachesys/ISCAgentCtrl status:

Last answer 3 November 2016 Last comment 7 November 2016
+ 1   0 3
596

views

+ 1

rating

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 ?

Last comment 10 March 2016
+ 1   0 6
0

answers

471

views

+ 1

rating

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?

 

 

Last answer 31 January 2017
0   0 1
0

comments

164

views

0

rating

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.

0   0 3
0

comments

141

views

0

rating

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

Last answer 29 March 2017 Last comment 30 March 2017
0   0 1
669

views

0

rating

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.

0   0 1
0

comments

183

views

0

rating

Hi All

I'm looking for some field experiences, lessons learned, or actual deployed solutions to the problem of replicating non-CACHE.DAT data in a mirrored Cache environment.  

Environment:

  • Operating System is IBM AIX
  • Hardware is IBM Power w/ virtualised storage
  • Cache 2017.1
  • 2x Production mirror members
  • 1x DR mirror member

 

There are a number of different data types that we're looking at mirroring, and a number of identified solutions.  The two main types of data to be mirrored outside of Cache mirroring are:

Last answer 22 May 2017
0   0 2
0

comments

220

views

0

rating

Hi, would really appreciate your advice on how I can restart the mirror-monitor. I've followed the instructions and restarted the mirror monitor, and still the status seems to be down. Can you point me to some resource or steps that I can follow ?

I logged into %SYS terminal and restarted the mirror monitor and it says that it is running

Last answer 24 December 2018 Last comment 30 December 2018
0   0 4
179

views

0

rating

InterSystems has corrected a defect that can result in data integrity problems in environments that use InterSystems mirroring in conjunction with parallel dejournaling. This problem exists for currently released Caché and Ensemble versions beginning with 2017.2 and for InterSystems IRIS Data Platform version 2018.1.

0   0 1
0

comments

103

views

0

rating

Hi Community!

Please find the Developer Community Video of the week:

Failover for Cloud and Wide-Area Networks 

 

0   0 1
0

comments

131

views

0

rating

Hi guys

I've added a new mirrored failover member to an existing one.

They are both Arbiter controlled.

When I do Add database to mirror on the primary I'm always getting an error. Missing Mirrored database.

I followed everything in the documentation and always get the same error.

I've copied the CACHE.dat file after umounting the database on both servers. then mounted them.

Could you help me out?

 

Kind Regards

Last answer 4 March 2019
0   0 1
0

comments

92

views

0

rating

I need to have both Cache and the Mirroring Arbiter startup when the HP UX system starts.  Having not worked on HP UX much I am not familiar with the method for accomplishing this.

I would appreciate any information or even sample scripts that would help resolve this.

Last answer 23 October 2017
0   0 1
0

comments

230

views

0

rating