Hi, What about using pure ACK mode ?
You can see an example with queue (same can be applied to topic) here: http://blog.nanthrax.net/?p=820 My point is: do you need XA as AFAIU you are using only JMS as resource (XA is required when you want to use the same transaction with different backends like JMS and database for instance) ? Regards JB On 03/09/2019 19:03, Benoit Fortin wrote: > We have a java application doing JMS subscriptions that is using Camel as > its JMS provider. > > The application is subscribing to a topic using XA. It consumes 1 message > in the queue, and then closes the XA transaction (each message is part of > an XA transaction). Then the application re-attaches itself to the topic to > start over the same process for each message. > > When there are no messages to process, the client waits for 45 seconds > (which is the XA transaction timeout) before closing the request and the XA > transaction and starting a new iteration. > > I have analyzed how this process is actually being done using a tcpdump, > and here is what I found: > > —— > > MQ Client --[XA_START]--> MQ Server > > MQ Client <--[XA_START_REPLY]-- MQ Server > > > MQ Client --[SPI (SUBSCRIBE)]--> MQ Server > > MQ Client <--[SPI REPLY]-- MQ Server > > > MQ Client --[REQUEST_MSGS]--> MQ Server > > MQ Client --[REQUEST_MSGS]--> MQ Server > > MQ Client <--[NOTIFICATION]-- MQ Server > > > MQ Client --[MQCLOSE]--> MQ Server > > MQ Client <--[MQCLOSE_REPLY]-- MQ Server > > > MQ Client --[XA_END]--> MQ Server > > MQ Client <--[XA_END_REPLY]-- MQ Server > > > MQ Client --[XA_COMMIT]--> MQ Server > > MQ Client <--[XA_COMMIT_REPLY]-- MQ Server > > —— > > This is process is on a durable subscription, so each of the iterations > (even when there is no message to consume) ends up generating I/O on the MQ > server (I think, mostly on the SYSTEM.DURABLE.SUBSCRIBER.QUEUE queue, where > MQ keeps trace of its subscribers). > > Having a somewhat high number of subscribers doing this process, the MQ > server ends up I/O bound, with +4000 IOPS on the MQ logs disks (even > outside of business hours, when there are no messages to consume). This > process also consumes ~3 CPU outside of business hours. > > I am a bit puzzled that using XA on pub/sub scales so bad, and I am > wondering if there is any way to implement this solution without doing so > much subscribe operations. > -- Jean-Baptiste Onofré jbono...@apache.org http://blog.nanthrax.net Talend - http://www.talend.com
