cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (JIRA)" <>
Subject [jira] [Commented] (CASSANDRA-9318) Bound the number of in-flight requests at the coordinator
Date Fri, 23 Oct 2015 15:26:28 GMT


Jonathan Ellis commented on CASSANDRA-9318:

bq. I'd like to resurrect this one and if time permits take it by following Jonathan's proposal
above, except I'd also like to propose an additional form of back-pressure at the coordinator->replica

The whole point of this ticket is to avoid the complexity of intra-node backpressure, and
instead basing coordinator -> client backpressure on the coordinator's local knowledge.
 (Which is not a perfect view of cluster state but it is a reasonable approximation, especially
since it can use its MessagingService state to guess replica problems, even without explicit
replica backpressure.)

We can always add explicit intra-node backpressure later, they are complementary.  But I'm
not sure it will be necessary and I want to avoid over-engineering the problem to start.

> Bound the number of in-flight requests at the coordinator
> ---------------------------------------------------------
>                 Key: CASSANDRA-9318
>                 URL:
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Ariel Weisberg
>            Assignee: Jacek Lewandowski
>             Fix For: 2.1.x, 2.2.x
> It's possible to somewhat bound the amount of load accepted into the cluster by bounding
the number of in-flight requests and request bytes.
> An implementation might do something like track the number of outstanding bytes and requests
and if it reaches a high watermark disable read on client connections until it goes back below
some low watermark.
> Need to make sure that disabling read on the client connection won't introduce other

This message was sent by Atlassian JIRA

View raw message