Hi, I have been experiencing locks with task queues since last week, specially when I use dynamic instances in my backends. During minutes, the CPU load goes to 0% on all instances of a given backend that only processes task queues; the queue keeps growing, but no single task is executed (and this happens with as few tasks as 10). After some time (minutes), it starts working again. The worst of all is that these locks are causing that some operations on datastore timeout, so our application enters a catastrophic spiral where everything starts to fail.
The lock is produced always executing one specific task, in the first instruction of the task, that is an access to Datastore. This access is just a "getObjectById()" from an enrity kind that only has one entity! After 30 seconds the query timeouts, and the task ends, but all other tasks keep locked in the same instruction. Then, after some time, everything starts working again. In my case I am using backends, and the backend that locks is dynamic with 2 instances, 6 concurrent requests max. We do JDO access to datastore inside the tasks, but I keep the JDO objects transient, to discard that the problems are due to JDO locks. Eduardo. -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine-java/-/WEIRLR4jRUEJ. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
