Pivotal Knowledge Base

Follow

deadlock - Process waits for ExclusiveLock on resource queue

Environment

Product Version
Pivotal Greenplum (GPDB) 4.3.x
OS All OS
Others  

Symptom

User assign to a resource queue get a deadlock message. 

Error Message:

"ERROR","40P01","deadlock detected","Process 76022 waits for ExclusiveLock on resource queue 9140473; blocked by process 75991. Process 75973 waits for ExclusiveLock on resource queue 9140473; blocked by process 76022."

Cause 

Most of the time this is a result of a user defined function with cursor calling another user defined function while logged in as a user assigned to resource queue. 

it is a known limitation of current resource queue implementation that it is possible to be in deadlock if you use functions that execute another SQL

Resolution

At the time of writing this article (29.09.16) There is no available resolution. The resource queue logic will be redesigned in the future and engineering is aware of the issue. 

Workaround: Customers needs to tune the resource queues and increase active statements as a workaround .

Comments

  • Avatar
    Gurupreet Singh Bhatia

    Thanks. is there any way to by-pass resource queue during querying to any table

  • Avatar
    Joe Murray

    Latest update as of 26th April, 2017

    Resource queues will be redesigned for 5.x and currently in progress. Tentatively this will be available in Q3 this year.

    Joe

Powered by Zendesk