wrunderwood commented on code in PR #96: URL: https://github.com/apache/solr/pull/96#discussion_r1327836121
########## solr/solr-ref-guide/modules/deployment-guide/pages/circuit-breakers.adoc: ########## @@ -24,12 +24,19 @@ resource configuration. Circuit breakers should be used when the user wishes to trade request throughput for a higher Solr stability. If circuit breakers are enabled, requests may be rejected under the condition of high node duress with HTTP error code 429 'Too Many Requests'. -It is up to the client to handle this error and potentially build a retrial logic as this should ideally be a transient situation. +It is up to the client to handle this error and potentially build retry logic as this should be a transient situation. + +In a sharded collection, when a circuit breaker trips on one shard, the entire query will fail, +even if the other shard requests succeed. This will multiply the failures seen by the end users. +Setting the `shards.tolerant=true` parameter on requests can help with graceful degradation when +circuit breaker thresholds are reached on some nodes. See the <<shards.tolerant Parameter>> for details. == Circuit Breaker Configurations All circuit breaker configurations are listed as independent `<circuitBreaker>` entries in `solrconfig.xml` as shown below. A circuit breaker can register itself to trip for query requests and/or update requests. By default only search requests are affected. A user may register multiple circuit breakers of the same type with different thresholds for each request type. +Configuring circuit breakers for update requests in a collection with NRT replicas can result in +inconsistent contents in different replicas. Review Comment: Sorry, thought I removed that and asked the question in this comment string. I'll pull it out. I don't have a super-deep understanding of NRT, but I think the replicas pull all outstanding updates from the tlog using real-time get, so that should be safe for lost update notifications. If it actually works that way... -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org
