[Progress Communities] [Progress OpenEdge ABL] Forum Post: RE: Activity: Performance Indicators - Latch timeouts

[George Potemkin]

Writeprobe test creates the predictable latch activity that highly unpredictably depends from Progress version: 11.6: (MTX + BIB) per recovery note + (MTX, 4*TXT, 2*TXQ) per transaction. 11.7: Nothing per recovery note + (2*MTX,3*TXT) per transaction. 12.0: (MTX + BIB) per recovery note + (1*MTX, 4*TXT, 2*TXQ, LKT) per transaction. Note that the code of writeprobe above creates only 3 recovery notes per transaction (RL_TBGN, RL_TMSAVE, RL_TEND) but the size of transaction can be increased by adding ‘i = 1 to 100’ to a sub-transaction’s block that will create an additional RL_TMSAVE note per loop. Some of these latches are obviously locked when a process already holds MTX latch. Can somebody explain when these latches are locked individually and when they are locked under the cover of MTX latch? If first case we should get the contention for a particular latch. In second case we will have the contention only for MTX latch. We can’t trust the “Owner” field in ‘Activity: Latch Counts‘ screen or in _Latch-Owner because the time to get this information for the whole set of latches is much longer than the typical duration of the latch locks. Nevertheless the couple of screens from the yesterday’s tests (it was V11.7.3): 05/01/19 Activity: Summary 16:12:37 05/01/19 16:12 to 05/01/19 16:12 (6 sec) Event Total Per Sec Commits 348622 58103.7 0 Servers, 101 Users (101 Local, 0 Remote, 100 Batch), 0 Apws 05/01/19 Activity: Latch Counts 16:12:37 05/01/19 16:12 to 05/01/19 16:12 (6 sec) ----- Locks ----- Naps Owner Total /Sec /Sec MTX 28 1394490 232415 2595 BIB 28 1050568 175094 0 TXT 28 1394486 232414 0 AIB -- 2 0 0 TXQ -- 697247 116207 0 BHT -- 105 17 0 BUF -- 30 5 0 BUF -- 60 10 0 BUF -- 60 10 0 BUF -- 60 10 0 05/01/19 Activity: Summary 16:13:32 05/01/19 16:13 to 05/01/19 16:13 (6 sec) Event Total Per Sec Commits 349029 58171.5 0 Servers, 101 Users (101 Local, 0 Remote, 100 Batch), 0 Apws 05/01/19 Activity: Latch Counts 16:13:32 05/01/19 16:13 to 05/01/19 16:13 (6 sec) ----- Locks ----- Naps Owner Total /Sec /Sec MTX 23 1396104 232684 2548 BIB 90 1051806 175301 0 TXT -- 1396107 232684 0 AIB -- 2 0 0 TXQ 14 698054 116342 0 BHT -- 119 19 0 BUF -- 34 5 0 BUF -- 68 11 0 BUF -- 68 11 0 BUF -- 68 11 0

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