problems with shared nothing Master/Slave deployment

[Liu fuming <li...@qq.com>]

The parameter sendFailIfNoSpace become useless in shared nothing Master/Slave
deployment.
The consumer is blocked when KahaDB store is full.



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Re: problems with shared nothing Master/Slave deployment

[Liu fuming <li...@qq.com>]

First,the sendFailIfNoSpace problem.This expression
context.isNetworkConnection()  returns true, so the
systemUsage.isSendFailIfNoSpace() method become uesless.
Second, consumer don't receive messages. I sent some big messages to full
fill the KahaDB store,and the thread is block in the Queue.waitForSpace()
method.Then I added 5 consumers to the brokers,the master finished its work
,and sent the ConsumerInfo command to the slave.The slave didn't react until
I changed the value of variables in waitForSpace() method to make it get
through. After that OpenWireFormat.unmarshal went on to unmarshal the
ConsumerInfo command.




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Re: problems with shared nothing Master/Slave deployment

[Torsten Mielke <to...@fusesource.com>]

On Nov 13, 2012, at 9:17 AM, Liu fuming wrote:

> The parameter sendFailIfNoSpace become useless in shared nothing Master/Slave
> deployment.
> The consumer is blocked when KahaDB store is full.


I don't see why a consumer would get blocked if the specified system limits are reached. Only producers should be blocked. The idea is that consumers can still process messages so that more space in the broker is freed to take the next message from the producer. 

Further I don't understand why a master slave setup would make a difference here. However is the master broker should behave just like an ordinary broker. The slave broker won't even startup and load kahadb as it can't acquire the lock on kahadb.

I have not tested this lately but would assume that this property works as explained and only affects the producer, not the consumer.


Regards,

Torsten Mielke
torsten@fusesource.com
tmielke.blogspot.com