What's the difference between User Queue and Client Queue

Matthias1 · March 7, 2022, 5:50pm

Hello all,

we’re using a quite outdated Version of Adabas on Solaris. Almost every week we get a NAT3255 on our Test environment. The only thing we can do is a shutdown and restart of the regarding Database. Now it’s clear to me that the problem is an overflow of the so called “client queue”. You can view the current size of the client queue using adaopr di=hi.

The user queue has no problem. The user queue value is rising up at the moringtime and goes back to a low value at the evening. The client queue is rising all the time. adaopr … free_clq doen’t really help.

My question is: What’s the difference between client queue and user queue?

Regards!

Matthias

Ralph_Zbrog · March 7, 2022, 6:26pm

User queue is controlled by NU; client queue by NCL. Try setting NCL marginally higher. (The documentation warns not to set NCL too high.)

wolfgang.winter · March 7, 2022, 7:58pm

If the Rsp 255 is caused by client queue entries not cleaned up properly due to sessions not closed nicely try
adaopr FREE_CLQ before the client queue runs full, once you hit the wall you won’t be able to communicate with the db anymore.

Matthias1 · March 8, 2022, 6:42am

Hello Wolfgang and Ralph,

and thanks for your replies. free_clq doesn’t really help - even if I do it before the client queue runs full. Sometimes the client queue is reduced by ~5 entries by free_clq. But the problem remains the same.

Just have a look at that highwater-statistics:

                       ADANUC Version 6.3.2.06
        Database 2        High Water Marks      on 24-FEB-2022 08:28:05

Area/Entry               Size      In Use  High Water    %      Date/Time
----------               ----      ------  ----------    -      ---------
User Queue                100           6          41   41 21-FEB-2022 16:31:50
Command Queue               -           1           3    - 18-FEB-2022 10:38:24
Hold Queue                  -           0       2,170    - 21-FEB-2022 09:43:35
Client Queue              100          53          69   69 23-FEB-2022 17:23:25 # free_clq deleted 8 before
HQ User Limit           4,000           -       2,169   54 21-FEB-2022 09:43:35
Threads                    20           1           3   15 23-FEB-2022 11:34:30
Workpool           16,777,216           0   4,194,320   25 17-FEB-2022 18:36:00
  ISN Sort          2,097,152           -         392    0 18-FEB-2022 16:01:33
  Complex Search    2,097,152           -           0    0
Attached Buffer    16,777,216     403,456     495,616    2 23-FEB-2022 17:42:16
ATBX       (MB)            20           0           0    0
Buffer Pool        41,943,040  41,872,384  41,934,848   99 17-FEB-2022 18:36:00
Protection Area        63,990
  Active Area          19,197           -          23    0 21-FEB-2022 10:12:27
Group Commit               50           1           1    2 17-FEB-2022 18:45:12
Transaction Time        1,800           -       1,800  100 18-FEB-2022 11:42:02



                       ADANUC Version 6.3.2.06
        Database 2        High Water Marks      on 25-FEB-2022 19:14:51

Area/Entry               Size      In Use  High Water    %      Date/Time
----------               ----      ------  ----------    -      ---------
User Queue                100          14          41   41 21-FEB-2022 16:31:50
Command Queue               -           1           6    - 24-FEB-2022 14:57:50
Hold Queue                  -           0       2,170    - 21-FEB-2022 09:43:35
Client Queue              100          77          82   82 25-FEB-2022 18:01:50 # free_clq deleted 4 before
HQ User Limit           4,000           -       2,169   54 21-FEB-2022 09:43:35
Threads                    20           1           5   25 24-FEB-2022 14:56:17
Workpool           16,777,216           0   4,194,320   25 17-FEB-2022 18:36:00
  ISN Sort          2,097,152           -         392    0 18-FEB-2022 16:01:33
  Complex Search    2,097,152           -     142,212    6 24-FEB-2022 17:27:17
Attached Buffer    16,777,216     603,136     698,368    4 25-FEB-2022 18:53:37
ATBX       (MB)            20           0           0    0
Buffer Pool        41,943,040  41,905,152  41,934,848   99 17-FEB-2022 18:36:00
Protection Area        63,990
  Active Area          19,197           -          23    0 21-FEB-2022 10:12:27
Group Commit               50           1           1    2 17-FEB-2022 18:45:12
Transaction Time        1,800           -       1,800  100 18-FEB-2022 11:42:02



                       ADANUC Version 6.3.2.06
        Database 2        High Water Marks      on 28-FEB-2022 08:35:01

Area/Entry               Size      In Use  High Water    %      Date/Time
----------               ----      ------  ----------    -      ---------
User Queue                100           5          41   41 21-FEB-2022 16:31:50
Command Queue               -           1           6    - 24-FEB-2022 14:57:50
Hold Queue                  -           0       2,170    - 21-FEB-2022 09:43:35
Client Queue              100          73          82   82 25-FEB-2022 18:01:50
HQ User Limit           4,000           -       2,169   54 21-FEB-2022 09:43:35
Threads                    20           1           5   25 24-FEB-2022 14:56:17
Workpool           16,777,216           0   4,194,320   25 17-FEB-2022 18:36:00
  ISN Sort          2,097,152           -         392    0 18-FEB-2022 16:01:33
  Complex Search    2,097,152           -     142,212    6 24-FEB-2022 17:27:17
Attached Buffer    16,777,216     582,656     698,368    4 25-FEB-2022 18:53:37
ATBX       (MB)            20           0           0    0
Buffer Pool        41,943,040  41,909,248  41,934,848   99 17-FEB-2022 18:36:00
Protection Area        63,990
  Active Area          19,197           -          23    0 21-FEB-2022 10:12:27
Group Commit               50           1           1    2 17-FEB-2022 18:45:12
Transaction Time        1,800           -       1,800  100 18-FEB-2022 11:42:02




                       ADANUC Version 6.3.2.06
        Database 2        High Water Marks      on 28-FEB-2022 15:13:02

Area/Entry               Size      In Use  High Water    %      Date/Time
----------               ----      ------  ----------    -      ---------
User Queue                100          23          41   41 21-FEB-2022 16:31:50
Command Queue               -           1           6    - 24-FEB-2022 14:57:50
Hold Queue                  -           0       2,170    - 21-FEB-2022 09:43:35
Client Queue              100          91          92   92 28-FEB-2022 15:12:53
HQ User Limit           4,000           -       2,169   54 21-FEB-2022 09:43:35
Threads                    20           1           5   25 24-FEB-2022 14:56:17
Workpool           16,777,216           0   4,194,320   25 17-FEB-2022 18:36:00
  ISN Sort          2,097,152           -         392    0 18-FEB-2022 16:01:33
  Complex Search    2,097,152           -     142,212    6 24-FEB-2022 17:27:17
Attached Buffer    16,777,216     706,560     707,584    4 28-FEB-2022 15:12:54
ATBX       (MB)            20           0           0    0
Buffer Pool        41,943,040  41,905,152  41,934,848   99 17-FEB-2022 18:36:00
Protection Area        63,990
  Active Area          19,197           -          23    0 21-FEB-2022 10:12:27
Group Commit               50           1           1    2 17-FEB-2022 18:45:12
Transaction Time        1,800           -       1,800  100 18-FEB-2022 11:42:02




                       ADANUC Version 6.3.2.06
        Database 2        High Water Marks      on  1-MAR-2022 17:21:41

Area/Entry               Size      In Use  High Water    %      Date/Time
----------               ----      ------  ----------    -      ---------
User Queue                100          13          17   17  1-MAR-2022 16:10:50
Command Queue               -           1           3    -  1-MAR-2022 11:43:45
Hold Queue                  -           0           3    -  1-MAR-2022 07:00:27
Client Queue              100          15          18   18  1-MAR-2022 16:10:34         #  just after restart of db
HQ User Limit           4,000           -           3    0  1-MAR-2022 07:00:27
Threads                    20           1           2   10  1-MAR-2022 08:57:46
Workpool           16,777,216           0   4,194,320   25 28-FEB-2022 19:04:37
  ISN Sort          2,097,152           -           0    0
  Complex Search    2,097,152           -           0    0
Attached Buffer    16,777,216      79,872      91,136    0  1-MAR-2022 16:10:46
ATBX       (MB)            20           0           0    0
Buffer Pool        41,943,040  41,926,656  41,940,992   99 28-FEB-2022 19:04:37
Protection Area        63,990
  Active Area          19,197           -           2    0  1-MAR-2022 09:22:49
Group Commit               50           1           1    2 28-FEB-2022 19:12:11
Transaction Time        1,800           -           0    0

Hilmar_Wantje6 · April 13, 2022, 9:39am

Hi all.
thanks for the infos about reaching the NCL limit.

What’s the difference between userqueue and clientqueue? i think NU shows the number of adaopr db=$DBID di=uq. but what is a client than?
TIA
Hilmar

Hilmar_Wantje6 · April 13, 2022, 10:03am

Hi
i reviewed my old documentations. some apps like WCP are using more than one thread for connecting to a database. is this the reason for differences between the NU and NCL numbers?

Regards
Hilmar

Matthias1 · June 10, 2022, 8:19am

Meanwhile I found the reason for this: There are some natural-zombie-processes. The adabas-uq-entry was killed (i don’t know if it’s timeout or using adaopr db=xx stop=xx) but the natural process is still alive and wasting a client queue entry. If you kill the natural process, the client queue is reduced…

system · September 8, 2022, 8:19am

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