Greetings, * Ghislain ROUVIGNAC (ghr@xxxxxxxxx) wrote: > Portworx says that on a running PostgreSQL it can: > > - replicate volumes for failover > - take snapshots of volumes > - backup volumes The downside with any snapshot-style approach is that it means that when you have a failure, you have to go through and replay all the WAL since the last checkpoint, which is single-threaded and can take a large amount of time. This is why PostgreSQL has streaming replication, where we are constantly sending WAL to the replica and replaying it immediately, and that also allows us to have synchronous replication that is quorum based and works with PostgreSQL, unlike what a snapshot level system would provide. When doing your testing, I'd strongly recommend that you have a large max_wal_size, run a large pgbench which writes a lot of data, and see how long a failover takes with this system. > Does someone use them in production ? > How reliable are these features ? > Are there performance impacts of snapshots ? I don't know anything about the actual utilization of this in production or if this implementation is reliable, just to be clear. My comments specifically are about the performance of using a snapshot-based approach (which could be this solution or various other ones). Thanks! Stephen
Attachment:
signature.asc
Description: PGP signature
