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https://issues.apache.org/jira/browse/CASSANDRA-3518?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13154920#comment-13154920
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Chris Goffinet edited comment on CASSANDRA-3518 at 11/22/11 7:08 AM:
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Radim,
I know what the Request Scheduler is.. please read my ticket more carefully.
{noformat}
# Scheduler Options vary based on the type of scheduler
# NoScheduler - Has no options
# RoundRobin
# - throttle_limit -- The throttle_limit is the number of in-flight
# requests per client. Requests beyond
# that limit are queued up until
# running requests can complete.
# The value of 80 here is twice the number of
# concurrent_reads + concurrent_writes.
{noformat}
number of in-flight requests per client. I want to a) do this per user b) break
it down so it's request/s not how many concurrent reads/writes in flight.
was (Author: lenn0x):
Radim,
I know what the Request Scheduler is.. please read my ticket more carefully.
# Scheduler Options vary based on the type of scheduler
# NoScheduler - Has no options
# RoundRobin
# - throttle_limit -- The throttle_limit is the number of in-flight
# requests per client. Requests beyond
# that limit are queued up until
# running requests can complete.
# The value of 80 here is twice the number of
# concurrent_reads + concurrent_writes.
number of in-flight requests per client. I want to a) do this per user b) break
it down so it's request/s not how many concurrent reads/writes in flight.
> Back pressure users by request/s instead of concurrent reads/writes
> -------------------------------------------------------------------
>
> Key: CASSANDRA-3518
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3518
> Project: Cassandra
> Issue Type: Bug
> Affects Versions: 1.0.2
> Reporter: Chris Goffinet
>
> We are running into use cases where it makes a lot of sense to have QoS at
> the request level per user. Imagine this case:
> I have a cluster that can do 100,000 req/s. But I want to limit the user to
> only being able to do either 50,000 read or write/s per second in the
> cluster. I rather give back pressure to the user then make the cluster fall
> down because the user tried to take down my cluster.
> Also another case we have is where you have experimental features and want to
> give access to certain group of customers and let them run experiments on
> data. You *dont* want them taking down the cluster, you rather make them fail
> fast, or slow them down. If I could limit a user to N req/s for reads or
> writes, instead of adding back pressure based on # of concurrent requests in
> each stage, this would go a long way for us.
> We have had a few incidents where spinning up new features caused unexpected
> load and we couldn't stop them without turning the feature off.
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