activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mohit Anchlia <mohitanch...@gmail.com>
Subject Re: Memory limit errors
Date Wed, 02 Jan 2013 21:02:41 GMT
Thanks for the info. I'll look at those parameter.

It does look like that I am using persistence based on below
"persistent=true" parameter. So can I safely assume that only one producer
gets blocked?

<broker xmlns="http://activemq.apache.org/schema/core"
brokerName="static-broker1" persistent="true"
dataDirectory="${activemq.data}">

On Wed, Jan 2, 2013 at 12:53 PM, Christian Posta
<christian.posta@gmail.com>wrote:

> Yah, it's probably best to figure out how things are being sent right now.
>
> If messages are sent async and without a producer window then you'll hit
> the type of flow control that you did.
>
> Messages are sent async by default if using non-persistent messages or
> during a transaction. The only time any synchronous communication will be
> done during a transaction is when you commit (or rollback).
>
> So you can set ActiveMQConnection#setAlwaysSyncSend which will always send
> sync for all types of sends (non-persistent and during a transaction). This
> will enable the type of flow control on the broker side that blocks only
> the one producer. The drawbacks are it has more network overhead and is
> likely slower. How much slower is something you may wish to measure.
> Depending on your application requirements, it might not be a big deal.
>
> You can also set the producer window on the client. The producer window
> establishes a client-side contract that basically says "I will only sned N
> number of bytes to you until I hear back that the message has been
> received" You can set this value (in number of bytes) on
> ActiveMQConnection#setProducerWindowSize. This will also achieve blocking
> only the one producer instead of the entire connection.
>
> Lastly, note that persistent messages are always sent synchronous so by
> default would block only the producer and not the entire connection.
>
>
> On Wed, Jan 2, 2013 at 1:40 PM, Mohit Anchlia <mohitanchlia@gmail.com
> >wrote:
>
> > Thanks! Sounds like there might be another way we can configure the flow
> > control that blocks only one producer? Do you have any recommendation on
> > what changes I should make to the config?
> >
> > On Wed, Jan 2, 2013 at 12:33 PM, Christian Posta
> > <christian.posta@gmail.com>wrote:
> >
> > > Enqueue count = number of messages sent to the queue
> > > Dequeue count = number of messages ack'd by the consumer
> > > Inflight count = number of messages sent to consumer's session (and are
> > not
> > > ack'd by consumer)
> > > Dispatch count = messages sent to the consumer (dequeue + inflight)
> > >
> > > I asked about the async sends because the producer flow control you hit
> > was
> > > the kind that will block the entire connection (instead of just
> blocking
> > > that one producer).
> > >
> > >
> > >
> > >
> > >
> > > On Wed, Jan 2, 2013 at 12:41 PM, Mohit Anchlia <mohitanchlia@gmail.com
> > > >wrote:
> > >
> > > > Thanks again! Is the dispatch queue size the one that relates to
> what's
> > > > held in memory?
> > > >
> > > > We are using mule and the endpoint has no transactions configured.
> What
> > > did
> > > > you mean by forcing async?
> > > >
> > > > On Wed, Jan 2, 2013 at 11:06 AM, Christian Posta
> > > > <christian.posta@gmail.com>wrote:
> > > >
> > > > > Correct. The memoryUsage is increased when messages are held in
> > memory.
> > > > > This happens when messages are paged in from the store. They are
> then
> > > > > dispatched to consumers and held until the consumer acks.
> > > > >
> > > > > In your case looks like a particular destination (eventsEndpoint)
> is
> > > > > filling up somehow. Can you look in JMX and see how many enqueued,
> > > > > dispatched, dequeued, inflight etc? Also check to see how many
> > > > > subscriptions to that destination, and see what those
> > dispatch-counter
> > > > and
> > > > > dispatch queue size looks like.
> > > > >
> > > > > BTW any chance you're sending (producers) using a transaction, or
> > > forcing
> > > > > sends to be async?
> > > > >
> > > > >
> > > > >
> > > > > On Wed, Jan 2, 2013 at 11:51 AM, Mohit Anchlia <
> > mohitanchlia@gmail.com
> > > > > >wrote:
> > > > >
> > > > > > So if I understand correctly I shouldn't be seeing this behaviour
> > > > unless
> > > > > > something is being held in memory. We ack immediately so I am
> kind
> > of
> > > > > > wondering what might be going on here. Is there a way to find
out
> > > what
> > > > > > might be happening here?
> > > > > >
> > > > > > On Wed, Jan 2, 2013 at 10:03 AM, Christian Posta
> > > > > > <christian.posta@gmail.com>wrote:
> > > > > >
> > > > > > > What info can you provide about how clients are consuming
from
> > the
> > > > > > queues?
> > > > > > > Any chance there are a bunch of messages "inflight" which
> haven't
> > > > been
> > > > > > > ack'd by the consumer?
> > > > > > >
> > > > > > >
> > > > > > > On Wed, Jan 2, 2013 at 10:20 AM, Mohit Anchlia <
> > > > mohitanchlia@gmail.com
> > > > > > > >wrote:
> > > > > > >
> > > > > > > > I see these messages being logged. Queues are setup
to use
> > > > persistent
> > > > > > > > store. I am wondering what's causing this messages
to get
> > > blocked.
> > > > I
> > > > > > see
> > > > > > > > there is a memoryLimit but if I am using persistent=true
then
> > > > should
> > > > > > this
> > > > > > > > be the desired behaviour?
> > > > > > > >
> > > > > > > >
> > > > > > > > 2013-01-02 05:06:13,388 | INFO |
> > > > > > > > Usage(default:memory:queue://eventsEndpoint:memory)
> > > > percentUsage=0%,
> > > > > > > > usage=0, limit=20971520,
> > > > > > > > percentUsageMinDelta=1%;Parent:Usage(default:memory)
> > > > > percentUsage=106%,
> > > > > > > > usage=22366029, limit=20971520, percentUsageMinDelta=1%:
> Usage
> > > > > Manager
> > > > > > > > Memory Limit reached. Producer
> > > > > > > > (ID:pfdamq301.ie.net-54582-1351809386355-2:1:1:1)
stopped to
> > > > prevent
> > > > > > > > flooding queue://eventsEndpoint. See
> > > > > > > >
> > > > > > > >
> > > > > > > >    <broker xmlns="http://activemq.apache.org/schema/core"
> > > > > > > > brokerName="static-broker1" persistent="true"
> > > > > > > > dataDirectory="${activemq.data}">
> > > > > > > >
> > > > > > > >         <!-- Destination specific policies using
destination
> > > names
> > > > or
> > > > > > > > wildcards -->
> > > > > > > >         <destinationPolicy>
> > > > > > > >             <policyMap>
> > > > > > > >                 <policyEntries>
> > > > > > > >                     <policyEntry queue=">"
> > > > producerFlowControl="true"
> > > > > > > > memoryLimit="20mb">
> > > > > > > >                         <deadLetterStrategy>
> > > > > > > >                           <individualDeadLetterStrategy
> > > > > > > queuePrefix="DLQ."
> > > > > > > > useQueueForQueueMessages="true" />
> > > > > > > >                         </deadLetterStrategy>
> > > > > > > >                     </policyEntry>
> > > > > > > >                     <policyEntry topic=">"
> > > > producerFlowControl="true"
> > > > > > > > memoryLimit="20mb">
> > > > > > > >                     </policyEntry>
> > > > > > > >                 </policyEntries>
> > > > > > > >             </policyMap>
> > > > > > > >         </destinationPolicy>
> > > > > > > >
> > > > > > > >         <!-- Use the following to configure how
ActiveMQ is
> > > exposed
> > > > > in
> > > > > > > JMX
> > > > > > > > -->
> > > > > > > >         <managementContext>
> > > > > > > >             <managementContext createConnector="true"/>
> > > > > > > >         </managementContext>
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > *Christian Posta*
> > > > > > > http://www.christianposta.com/blog
> > > > > > > twitter: @christianposta
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > *Christian Posta*
> > > > > http://www.christianposta.com/blog
> > > > > twitter: @christianposta
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > *Christian Posta*
> > > http://www.christianposta.com/blog
> > > twitter: @christianposta
> > >
> >
>
>
>
> --
> *Christian Posta*
> http://www.christianposta.com/blog
> twitter: @christianposta
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message