I would like to mention the main reasons I had investigated colocated backups was to see if we could better utilize the resources of the hot backup and to simplify configuration and deployment with a single configuration vs maintaining separate live and backup configurations. I never successfully got colocation working so I am not partial to that particular feature but I did want to mention some of its merits despite its evident downsides.
Ryan Yeats On 2/10/20, 12:21 PM, "Christopher Shannon" <[email protected]> wrote: +1, it never really made a whole lot of sense to me to have a backup in the same JVM when a new JVM can be spun up easily and is much easier to support. Also many different errors that might cause a failover to be needed would affect the JVM such as OOM, etc. On Mon, Feb 10, 2020 at 2:14 PM Justin Bertram <[email protected]> wrote: > Artemis currently has the ability to configure both a live and a backup > server in the same JVM. This is referred to as "colocated" brokers. > > The original use-case for this functionality was very early cloud > infrastructure where durable, attached storage was not readily available. > However, since the development of this feature most (if not all) cloud > environments support durable storage separate from the broker so that if > the broker goes down a new, identical broker can be spun-up quickly and > attached to the same storage. This provides high availability without the > need for any idle backups or replication of any kind which functionally > nullifies this feature. > > Aside from this, it turns out that (surprise!) configuring & running > multiple brokers in the same JVM is difficult and error-prone not to > mention dynamically coordinating the acquisition of backups in a running > cluster and protecting against split-brain. I was able to quickly search > and find 5 open Jiras for colocated issues (of course, there may be more): > > ARTEMIS-452 - Scale down with colocated backup failing when using > replication > ARTEMIS-2165 - Not having backup available after restart in colocated > configuration > ARTEMIS-2609 - Ha-policy collocated not working. > ARTEMIS-2452 - group-name ignored in shared store colocated setup > ARTEMIS-1863 - Colocated Replicating Cluster Ends Up in an Infinite > Quorum Vote Loop After Failover and Restart > > At this point I recommend that we deprecate this feature and steer users > who want this kind of functionality to either existing cloud infrastructure > options or multiple, distinct brokers on the same hardware (i.e. outside > the cloud). > > What are your thoughts? > > > Justin >
