Re: MQ behaviour - persistent messages availability when the qmgr crashes
Sorry I didn't answer all the question before as Dennis did. You wouls expect that your input to the transaction is recoverable also. So when the process starts again you can restart that transaction as if nothing happened (sometimes almost). This is one of the benifits of running under a LUW. If you input is not covered under this you must plann a way to do it. Otherwise you break the processing line of thought. bobbee From: "Miller, Dennis" <[EMAIL PROTECTED]> Reply-To: MQSeries List <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Subject: Re: MQ behaviour - persistent messages availability when the qmgr crashes Date: Fri, 30 May 2003 10:30:45 -0700 The message might be logged, but it cannot be recovered. A qmgr crash effects a backout, but I would say it happens more after the fact, rather than "just before". > -Original Message- > From: Diwakar S Yammanuru [SMTP:[EMAIL PROTECTED] > Sent: Friday, May 30, 2003 7:59 AM > To: [EMAIL PROTECTED] > Subject: MQ behaviour - persistent messages availability when the qmgr crashes > > Hello there. > When an application puts a persistent msg on a queue and if the corresponding > qmgr fails before the messge is committed/backed out . can the message > still be recovered after the qmgr comes up ? I mean, is the message logged ? > > Does a qmgr perform a commit/backout just before it crashes, if it is the > transaction manager ? > > Forgive me if the questions sound silly. > > thnx. > Diwakar. > > > > American Express made the following > annotations on 05/30/2003 07:58:49 AM > -- > ** > > "This message and any attachments are solely for the intended recipient and may contain confidential or privileged information. If you are not the intended recipient, any disclosure, copying, use, or distribution of the information included in this message and any attachments is prohibited. If you have received this communication in error, please notify us by reply e-mail and immediately and permanently delete this message and any attachments. Thank you." > > ** > > > == > > Instructions for managing your mailing list subscription are provided in > the Listserv General Users Guide available at http://www.lsoft.com > Archive: http://vm.akh-wien.ac.at/MQSeries.archive Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive _ Add photos to your e-mail with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
Re: MQ behaviour - persistent messages availability when the qmgr crashes
Here is a situation: An application is running, It reads a Q or 2 writes a Q or 2 all in a UOW and the QMGR goes down now part of that UOW is a PUT to a queue prior to the MQCOMIT to ICE the processing deal. Are the messages comitted when the QMGR comes back up? Mr Diwakar never said he was in the middle of a MQCOMIT or MQBACK he just said "BEFORE" they were comitted. Granted if you issue a MQCOMIT/MQBACK this may or may not be the case but what are the implications when the QMGR takes a holiday in the middle of your processing (not necessarly in the middle of a direct communication with him/her). bobbee From: John Scott <[EMAIL PROTECTED]> Reply-To: MQSeries List <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Subject: Re: MQ behaviour - persistent messages availability when the qmgr crashes Date: Fri, 30 May 2003 17:10:19 - I think there's a subtle "middlepoint" here. You may not have received an RC=0 on the commit, but the messages may have been committed anyway. There would be a small window of opportunity where MQ has completed the commit, but before it could return RC=0 to the app, it all goes pear shaped. I think the only guarantee is that either all the messages in the UOW will be committed or all will be backed out. You will never be able to get a situation where some of the messages in a UOW get committed and other in the same UOW get backed out. I've seen other threads talking about this with respect to MQClient and to quote Paul Clarke: "The semantics of messaging is exactly the same for a client as for a locally connected application. In other words, in order to do reliable messaging in a local application you must follow a certain set of rules like issuing MQPUTs and MQGETs under transactions etc. These rules are exactly the same for a client. One area which often concerns programmers is the MQCMIT call. What happens if you lose your network half way through an MQCMIT verb and get a MQRC_CONNECTION_BROKEN reason code. Did the transaction commit or didn't it ? Well, this is the same for a local application, you are not guaranteed to get a definitive answer on your transaction commit even for the local application. If you really care, you must do some 'known' action (like put a message to a queue) that you can subsequently check the next time you connect." Regards John. -Original Message- From: Robert Broderick [mailto:[EMAIL PROTECTED] Sent: 30 May 2003 15:28 To: [EMAIL PROTECTED] Subject: Re: MQ behaviour - persistent messages availability when the qmgr crashes If you application didn't receive the RC=0 I believe it would be considered an inflight transaction and would be backed out upon QMGR restart. >From: Diwakar S Yammanuru <[EMAIL PROTECTED]> >Reply-To: MQSeries List <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: MQ behaviour - persistent messages availability when the qmgr > crashes >Date: Fri, 30 May 2003 10:58:39 -0400 > >Hello there. >When an application puts a persistent msg on a queue and if the >corresponding qmgr fails before the messge is committed/backed out >. can the message still be recovered after the qmgr comes up ? I >mean, is the message logged ? > >Does a qmgr perform a commit/backout just before it crashes, if it is >the transaction manager ? > >Forgive me if the questions sound silly. > >thnx. >Diwakar. > > > >American Express made the following > annotations on 05/30/2003 07:58:49 AM >--- >--- >*** *** > > "This message and any attachments are solely for the intended >recipient and may contain confidential or privileged information. If >you are not the intended recipient, any disclosure, copying, use, or >distribution of the information included in this message and any >attachments is prohibited. If you have received this communication in >error, please notify us by reply e-mail and immediately and permanently >delete this message and any attachments. Thank you." > >*** >*** > > >=== >=== > >Instructions for managing your mailing list subscription are provided >in the Listserv General Users Guide available at http://www.lsoft.com >Archive: http://vm.akh-wien.ac.at/MQSeries.archive _ Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail Instructions for managing your mailing list subscription are provided in the Listserv Gene
Re: MQ behaviour - persistent messages availability when the qmgr crashes
The message might be logged, but it cannot be recovered. A qmgr crash effects a backout, but I would say it happens more after the fact, rather than "just before". > -Original Message- > From: Diwakar S Yammanuru [SMTP:[EMAIL PROTECTED] > Sent: Friday, May 30, 2003 7:59 AM > To: [EMAIL PROTECTED] > Subject: MQ behaviour - persistent messages availability when the qmgr > crashes > > Hello there. > When an application puts a persistent msg on a queue and if the corresponding > qmgr fails before the messge is committed/backed out . can the message > still be recovered after the qmgr comes up ? I mean, is the message logged ? > > Does a qmgr perform a commit/backout just before it crashes, if it is the > transaction manager ? > > Forgive me if the questions sound silly. > > thnx. > Diwakar. > > > > American Express made the following > annotations on 05/30/2003 07:58:49 AM > -- > ** > > "This message and any attachments are solely for the intended recipient and may > contain confidential or privileged information. If you are not the intended > recipient, any disclosure, copying, use, or distribution of the information included > in this message and any attachments is prohibited. If you have received this > communication in error, please notify us by reply e-mail and immediately and > permanently delete this message and any attachments. Thank you." > > ** > > > == > > Instructions for managing your mailing list subscription are provided in > the Listserv General Users Guide available at http://www.lsoft.com > Archive: http://vm.akh-wien.ac.at/MQSeries.archive Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
Re: MQ behaviour - persistent messages availability when the qmgr crashes
I think there's a subtle "middlepoint" here. You may not have received an RC=0 on the commit, but the messages may have been committed anyway. There would be a small window of opportunity where MQ has completed the commit, but before it could return RC=0 to the app, it all goes pear shaped. I think the only guarantee is that either all the messages in the UOW will be committed or all will be backed out. You will never be able to get a situation where some of the messages in a UOW get committed and other in the same UOW get backed out. I've seen other threads talking about this with respect to MQClient and to quote Paul Clarke: "The semantics of messaging is exactly the same for a client as for a locally connected application. In other words, in order to do reliable messaging in a local application you must follow a certain set of rules like issuing MQPUTs and MQGETs under transactions etc. These rules are exactly the same for a client. One area which often concerns programmers is the MQCMIT call. What happens if you lose your network half way through an MQCMIT verb and get a MQRC_CONNECTION_BROKEN reason code. Did the transaction commit or didn't it ? Well, this is the same for a local application, you are not guaranteed to get a definitive answer on your transaction commit even for the local application. If you really care, you must do some 'known' action (like put a message to a queue) that you can subsequently check the next time you connect." Regards John. -Original Message- From: Robert Broderick [mailto:[EMAIL PROTECTED] Sent: 30 May 2003 15:28 To: [EMAIL PROTECTED] Subject: Re: MQ behaviour - persistent messages availability when the qmgr crashes If you application didn't receive the RC=0 I believe it would be considered an inflight transaction and would be backed out upon QMGR restart. >From: Diwakar S Yammanuru <[EMAIL PROTECTED]> >Reply-To: MQSeries List <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: MQ behaviour - persistent messages availability when the qmgr > crashes >Date: Fri, 30 May 2003 10:58:39 -0400 > >Hello there. >When an application puts a persistent msg on a queue and if the >corresponding qmgr fails before the messge is committed/backed out >. can the message still be recovered after the qmgr comes up ? I >mean, is the message logged ? > >Does a qmgr perform a commit/backout just before it crashes, if it is >the transaction manager ? > >Forgive me if the questions sound silly. > >thnx. >Diwakar. > > > >American Express made the following > annotations on 05/30/2003 07:58:49 AM >--- >--- >*** *** > > "This message and any attachments are solely for the intended >recipient and may contain confidential or privileged information. If >you are not the intended recipient, any disclosure, copying, use, or >distribution of the information included in this message and any >attachments is prohibited. If you have received this communication in >error, please notify us by reply e-mail and immediately and permanently >delete this message and any attachments. Thank you." > >*** >*** > > >=== >=== > >Instructions for managing your mailing list subscription are provided >in the Listserv General Users Guide available at http://www.lsoft.com >Archive: http://vm.akh-wien.ac.at/MQSeries.archive _ Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive ** Click here to visit the Argos home page http://www.argos.co.uk The information contained in this message or any of its attachments may be privileged and confidential, and is intended exclusively for the addressee. The views expressed may not be official policy, but the personal views of the originator. If you are not the intended addressee, any disclosure, reproduction, distribution, dissemination or use of this communication is not authorised. If you have received this message in error, please advise the sender by using your reply facility in your e-mail software. All messages sent and received by Argos Ltd are monitored for virus, high risk file extensions, and inappropriate content. As a result users should be aware that mail
Re: MQ behaviour - persistent messages availability when the qmgr crashes
If you application didn't receive the RC=0 I believe it would be considered an inflight transaction and would be backed out upon QMGR restart. From: Diwakar S Yammanuru <[EMAIL PROTECTED]> Reply-To: MQSeries List <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Subject: MQ behaviour - persistent messages availability when the qmgr crashes Date: Fri, 30 May 2003 10:58:39 -0400 Hello there. When an application puts a persistent msg on a queue and if the corresponding qmgr fails before the messge is committed/backed out . can the message still be recovered after the qmgr comes up ? I mean, is the message logged ? Does a qmgr perform a commit/backout just before it crashes, if it is the transaction manager ? Forgive me if the questions sound silly. thnx. Diwakar. American Express made the following annotations on 05/30/2003 07:58:49 AM -- ** "This message and any attachments are solely for the intended recipient and may contain confidential or privileged information. If you are not the intended recipient, any disclosure, copying, use, or distribution of the information included in this message and any attachments is prohibited. If you have received this communication in error, please notify us by reply e-mail and immediately and permanently delete this message and any attachments. Thank you." ** == Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive _ Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
MQ behaviour - persistent messages availability when the qmgr crashes
Hello there. When an application puts a persistent msg on a queue and if the corresponding qmgr fails before the messge is committed/backed out . can the message still be recovered after the qmgr comes up ? I mean, is the message logged ? Does a qmgr perform a commit/backout just before it crashes, if it is the transaction manager ? Forgive me if the questions sound silly. thnx. Diwakar. American Express made the following annotations on 05/30/2003 07:58:49 AM -- ** "This message and any attachments are solely for the intended recipient and may contain confidential or privileged information. If you are not the intended recipient, any disclosure, copying, use, or distribution of the information included in this message and any attachments is prohibited. If you have received this communication in error, please notify us by reply e-mail and immediately and permanently delete this message and any attachments. Thank you." ** == Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
