++ 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.

Hi, Community!

Check a new session recording from Global Summit 2017:

Mirror, Mirror, Which Should I Choose?

https://www.youtube.com/embed/NmMfE14RdDs
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I have Ensemble/Healthshare running in a production environment which is setup with a mirror failover and an arbiter sitting between them.

In the event of a failover we have a number of connections that need stopping/monitoring and starting in a certain order.

Is there a programmatic way we can detect the failover and stop certain services and operations immediately and then start them up again in the required order, checking their connection state before starting the next connection.

Looking through Mirroring routines sources, I've noticed these terms, while even the latest documentation keeps silence on them. I'm just curious what are they, and how to configure / to use them?

Hi Community!

Please find the Developer Community Video of the week:

Failover for Cloud and Wide-Area Networks

https://www.youtube.com/embed/da-UegJsjO4
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Check the new video on Developer Community YouTube Channel:

Mirroring - Architecting for Throughput

In this video, learn how to provide high availability (HA) and disaster recovery (DR) in diverse architectures that demand high performance, including replication over long distances.

Enjoy!

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

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?

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?

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.

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.

Does anyone know any sites who configure an async reporting member to connect to two different failover mirroring sets ?

I know this is supported, but I would like to know how it is working in real world systems.

Any information would be appreciated.

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.

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 ?