PQ Slave Process Hung On Gc Current Request For Long Time In RAC (Doc ID 2668586.1)

Last updated on JULY 20, 2024

Applies to:

Symptoms

• Parallel query coordinator process hung on 'PX Deq: Execute Reply' for several hours.
  
  
      344: USER ospid 48254 sid 2293 ser 27153, waiting for 'PX Deq: Execute Reply'  <<<<<<<
           Cmd: SELECT
  
  
  
• PQ slave process hung on 'gc current request' for several hours.
  
  
     Current Wait Stack:
      0: waiting for 'gc current request'
         file#=0x6, block#=0x1c214d3f, id#=0x2010001
         wait_id=646192 seq_num=59172 snap_id=1
         wait times: snap=292 min 27 sec, exc=292 min 27 sec, total=292 min 27 sec *<<<<<<<<<<<
         wait times: max=infinite, heur=292 min 27 sec
         wait counts: calls=14039 os=14039
         in_wait=1 iflags=0x5a0
• Systemstate dump trace shows that PQ slave process was trying to convert the buffer from shared to exclusive.
  
  
             pin: 'kdiwh15: kdifxs' pinwait: 'gc current request'
                 addr: 0xffd4fc0d8 obj: 1867461 cls: DATA
                 bscn: 0x4203f0a455 seq: 1 bflg: 0x4
                 index leaf (xid: 0x0.0.0 opcode: none lock: 0)
                      GCS CLIENT 0x18def88078,90 resp[(nil),0x1c214d3f.6] pkey 0.6.1867461                      lock domid 0, res domid 0
                        grant 1 cvt 2 mode 0x1 role 0x8 st 0x101 lst 0x220 GRANTQ rl LOCAL　*<<<<<<<<<<<(2)