When there's a performance issue, whether for all users on the system or a single process, the shortest path to understanding the root cause is usually to understand what the processes in question are spending their time doing.  Are they mostly using CPU to dutifully march through their algorithm (for better or worse); or are they mostly reading database blocks from disk; or mostly waiting for something else, like LOCKs, ECP or database block collisions?

Tools to help answer the questions above have always been available in various forms.

While the integrity of Caché and InterSystems IRIS databases is completely protected from the consequences of system failure, physical storage devices do fail in ways that corrupt the data they store.  For that reason, many sites choose to run regular database integrity checks, particularly in coordination with backups to validate that a given backup could be relied upon in a disaster.  Integrity check may also be acutely needed by the system administrator in response to a disaster involving storage corruption.

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.

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.