We did some explorations on excluding reads from the leader in a TLOG + PULL cloud. When updates are heavy we do observer query throughput and latency improvement. Added the patch we have bee testing https://issues.apache.org/jira/secure/attachment/13026792/SOLR-15472.patch
On Fri, Jun 11, 2021 at 11:43 AM Bram Van Dam <bram.van...@intix.eu> wrote: > On 11/06/2021 00.28, Walter Underwood wrote: > > Are you trying to send queries to less loaded machines? If so, this > won’t do that. > > Leaders only do a little bit more work than followers. All indexing > processing is local > > and that is most of the CPU usage. > > I suspect that depends on the type of replica. > > Reducing the load on leaders seems like a valuable feature. We've > observed cases where a high query load on leaders caused it to become > unresponsive, resulting in a cascade of failures, eventually rendering > an entire cluster unusable. > > In fact, it would also be useful to be able to direct certain queries > *only* to leaders when you know that replicas are lagging behind. > > - Bram >
