| Author |
Message |
 Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
 Forum: IBM MQ Performance Monitoring Posted: Mon Dec 21, 2015 7:18 am Subject: How can I check if read-ahead is actually enabled? |
All right, seems like the issue is unrelated to encoding in the end.
I tried 2 more things:
- Changing the Encoding metadata in the dumpfile to 546 and retrying: still slow
- Downloading the mess ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Mon Dec 21, 2015 2:08 am Subject: How can I check if read-ahead is actually enabled? |
For the record, I am adding all the meta info I can have about the messages.
Production (slow)
****Message descriptor****
StrucId : 'MD ' Version : 2
Report : 0 MsgType ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Mon Dec 21, 2015 1:56 am Subject: How can I check if read-ahead is actually enabled? |
Are you reading messages at the same time as you are writing them - from whatever you are using instead of qload?
No, just reading. I do not touch the production queue anymore now that I can repro ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Fri Dec 18, 2015 7:07 am Subject: How can I check if read-ahead is actually enabled? |
So you have the same CCSID but a different encoding... What is the FORMAT on the MQMD of your messages as shown by the browse tool? 
I get
Format : 'MQSTR '
Now, what I di ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Fri Dec 18, 2015 5:21 am Subject: How can I check if read-ahead is actually enabled? |
Ok, I compared some test messages with what I get from my prod queue. The only difference that seems significant is the encoding!
Production message:
Encoding : 273 CodedCharSetId : 8 ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Fri Dec 18, 2015 3:05 am Subject: How can I check if read-ahead is actually enabled? |
All right, I just did an interesting test: I copied about 26000 messages from my production queue to a file, then to my test queue. Now I get the same problem on the test queue!
The thing is, I che ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Wed Dec 16, 2015 6:26 am Subject: How can I check if read-ahead is actually enabled? |
This code is still not faster when used with the production queue, though. If anything, the option makes the code slower.
What option? Please be a bit more precise when you post.
Sorry. I am ta ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Wed Dec 16, 2015 4:50 am Subject: How can I check if read-ahead is actually enabled? |
Ok, I found what caused my code to exit after one message when pulling out of the production queue. I moved the lines
md = pymqi.MD()
gmo = pymqi.GMO()
... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Tue Dec 15, 2015 9:39 am Subject: How can I check if read-ahead is actually enabled? |
Edit: quoted myself instead of editing my message.
I wanted to add that it probably has to do with CMQC.MQOO_INPUT_AS_Q_DEF which now gets the READ_AHEAD as part of the queue definition settings. ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Tue Dec 15, 2015 9:37 am Subject: How can I check if read-ahead is actually enabled? |
With CURDEPTH(0), ReasonCode 2033 is appropriate - no message available.
I ran this command after I emptied the queues. When my code was running the queues were full.
See your test queue set up
... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Tue Dec 15, 2015 7:18 am Subject: How can I check if read-ahead is actually enabled? |
| No reason apart from the fact I tend to only use threads whenever strictly necessary because they are harder to debug. So I just tried changing to MQGMO_WAIT, because if it solves my problem, I am hap ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Tue Dec 15, 2015 5:56 am Subject: How can I check if read-ahead is actually enabled? |
I managed to have READ_AHEAD working on a small example! I uploaded the script as a
$ time QUEUE_NAME=TEST.Q READ_AHEAD=1 ./read_ahead_test
read_ahead_test:: Starting.
read_ahead_test: ... |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Tue Dec 15, 2015 2:21 am Subject: How can I check if read-ahead is actually enabled? |
No, my get options are
gmo.Options = CMQC.MQGMO_NO_WAIT | \
CMQC.MQGMO_FAIL_IF_QUIESCING
|
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Mon Dec 14, 2015 1:14 pm Subject: How can I check if read-ahead is actually enabled? |
| No, it is a brand new channel specially created for that purpose. |
| Topic: How can I check if read-ahead is actually enabled? |
chmd
Replies: 44
Views: 86306
|
Forum: IBM MQ Performance Monitoring Posted: Mon Dec 14, 2015 8:27 am Subject: How can I check if read-ahead is actually enabled? |
All right!
So it turns out that the traces do not go to /var/mqm. In my case, they go to a directory IBM/MQ/data/trace that is created in the current directory.
I cleaned it and rerun the progra ... |
