Connections hang

Hi fellows, from time to time, not quite often but believe me its pretty annoying, happens that connections from remote servers or applications - every onsoctcp connections - to our main IDS box just hang without any apparent reason. Anyways local connections (e.g. a simple "dbaccess my_database") work fine! What parameters onconfig should i check or tune? Any onstat option? NETTYPE is set to soctcp,2,100,NET, all logical logs are backed up, there is plenty of swap space (for the OS as well as for informix TMP dbspaces), CPU is mostly idle, eliminated most busy sessions and some more at random pick from "onstat -u" to reduce their number, chache ratios are OK, locks are at normal level, network is working OK at full speed. Up to now, sincerely do not know what else to check. The box is IDS 9.40 on RedHat 7.3. Any help is really welcome

Can you reproduce the problem? You could start by determining what is happening to the session when the process is hung. That will tell you whether it is trying to do something in the engine or point you in another direction. You cold also run the application with set explain on to determine whether one sql is poor or whether you have too many sqls for your server to handle in a reasonable time. MW > -----Original Message----- > From: forum.subscriber@iiug.org > [mailto:forum.subscriber@iiug.org] On Behalf Of ESTEBAN RIEZNIK > Sent: Saturday, 16 April 2005 7:21 a.m. > To: ids@iiug.org > Subject: Connections hang [4728] > > Hi fellows, > > from time to time, not quite often but believe me its pretty > annoying, happens that connections from remote servers or > applications - every onsoctcp connections - to our main IDS > box just hang without any apparent reason. Anyways local > connections (e.g. a simple "dbaccess my_database") work fine! > > What parameters onconfig should i check or tune? Any onstat option? > > NETTYPE is set to soctcp,2,100,NET, all logical logs are > backed up, there is plenty of swap space (for the OS as well > as for informix TMP dbspaces), CPU is mostly idle, eliminated > most busy sessions and some more at random pick from "onstat > -u" to reduce their number, chache ratios are OK, locks are > at normal level, network is working OK at full speed. Up to > now, sincerely do not know what else to check. > > The box is IDS 9.40 on RedHat 7.3. > > Any help is really welcome > > > >

You might have tried all the below, if not 1. What is the status of the engine "onstat - ". Is it online or is it in Blocked CKPT state. Might be it is waiting on a check point. 2. What is the status of each session "onstat -u ", third column flags. The first character/flag would tell you the status of the session. You can get the explanation for each status from the manuals. It could be C/Y/-. 3. Have you tried onstat -g ntu. It tells you about the threads. 4. onstat -g act. This tells you whether a thread is running. If you don't see them moving, then that session/thread could be loading your CPU. 5. onstat -g wai. This tells you the threads that are waiting. 6. When it hangs, do you recycle the instance. Try getting some statistics. "Onstat -a" could take some time and space. Thank you, Kannan Thirugnanam -----Original Message----- From: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org] On Behalf Of Murray Wood.... Sent: Sunday, April 17, 2005 6:21 PM To: ids@iiug.org Subject: RE: Connections hang [4730] Can you reproduce the problem? You could start by determining what is happening to the session when the process is hung. That will tell you whether it is trying to do something in the engine or point you in another direction. You cold also run the application with set explain on to determine whether one sql is poor or whether you have too many sqls for your server to handle in a reasonable time. MW > -----Original Message----- > From: forum.subscriber@iiug.org > [mailto:forum.subscriber@iiug.org] On Behalf Of ESTEBAN RIEZNIK > Sent: Saturday, 16 April 2005 7:21 a.m. > To: ids@iiug.org > Subject: Connections hang [4728] > > Hi fellows, > > from time to time, not quite often but believe me its pretty > annoying, happens that connections from remote servers or > applications - every onsoctcp connections - to our main IDS > box just hang without any apparent reason. Anyways local > connections (e.g. a simple "dbaccess my_database") work fine! > > What parameters onconfig should i check or tune? Any onstat option? > > NETTYPE is set to soctcp,2,100,NET, all logical logs are > backed up, there is plenty of swap space (for the OS as well > as for informix TMP dbspaces), CPU is mostly idle, eliminated > most busy sessions and some more at random pick from "onstat > -u" to reduce their number, chache ratios are OK, locks are > at normal level, network is working OK at full speed. Up to > now, sincerely do not know what else to check. > > The box is IDS 9.40 on RedHat 7.3. > > Any help is really welcome > > > >

The most suspicious was the following, several annoyng 27001 error: 19:40:57 Maximum server connections 28 19:41:15 listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred during connection attempt. 19:42:18 listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred during connection attempt. The problem stayed even after tuning poll threads stuff, and even after rebooting server, with just very few connections. onstat, netstat et al. showed nothing suspicious. The listener thread was still screwed up. Due to lack of time for further in-depth analysis, a mate changed the port numbers of all the instances and IDS surprisingly started working fine again. We still can not figure out what could have happened. Never before in more than 1 yr. We *** suspect *** of a crippled remote server / router on the same day possibly sending corrupted data, but not sure yet. Unfortunately we can not reproduce the problem, but it would help for sure. Thanx a lot you guys for your help. I'll have your advices in account for next time. All the best. -----Mensaje original----- De: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org] En nombre de Thirugnanam.... Enviado el: Lunes, 18 de Abril de 2005 11:13 a.m. Para: ids@iiug.org Asunto: RE: Connections hang [4735] You might have tried all the below, if not 1. What is the status of the engine "onstat - ". Is it online or is it in Blocked CKPT state. Might be it is waiting on a check point. 2. What is the status of each session "onstat -u ", third column flags. The first character/flag would tell you the status of the session. You can get the explanation for each status from the manuals. It could be C/Y/-. 3. Have you tried onstat -g ntu. It tells you about the threads. 4. onstat -g act. This tells you whether a thread is running. If you don't see them moving, then that session/thread could be loading your CPU. 5. onstat -g wai. This tells you the threads that are waiting. 6. When it hangs, do you recycle the instance. Try getting some statistics. "Onstat -a" could take some time and space. Thank you, Kannan Thirugnanam -----Original Message----- From: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org] On Behalf Of Murray Wood.... Sent: Sunday, April 17, 2005 6:21 PM To: ids@iiug.org Subject: RE: Connections hang [4730] Can you reproduce the problem? You could start by determining what is happening to the session when the process is hung. That will tell you whether it is trying to do something in the engine or point you in another direction. You cold also run the application with set explain on to determine whether one sql is poor or whether you have too many sqls for your server to handle in a reasonable time. MW > -----Original Message----- > From: forum.subscriber@iiug.org > [mailto:forum.subscriber@iiug.org] On Behalf Of ESTEBAN RIEZNIK > Sent: Saturday, 16 April 2005 7:21 a.m. > To: ids@iiug.org > Subject: Connections hang [4728] > > Hi fellows, > > from time to time, not quite often but believe me its pretty > annoying, happens that connections from remote servers or > applications - every onsoctcp connections - to our main IDS > box just hang without any apparent reason. Anyways local > connections (e.g. a simple "dbaccess my_database") work fine! > > What parameters onconfig should i check or tune? Any onstat option? > > NETTYPE is set to soctcp,2,100,NET, all logical logs are > backed up, there is plenty of swap space (for the OS as well > as for informix TMP dbspaces), CPU is mostly idle, eliminated > most busy sessions and some more at random pick from "onstat > -u" to reduce their number, chache ratios are OK, locks are > at normal level, network is working OK at full speed. Up to > now, sincerely do not know what else to check. > > The box is IDS 9.40 on RedHat 7.3. > > Any help is really welcome > > > > AVISO LEGAL: Esta informacion es privada y confidencial y esta dirigida unicamente a su destinatario. Si usted no es el destinatario original de este mensaje y por este medio pudo acceder a dicha informacion por favor elimine el mensaje. La distribucion o copia de este mensaje esta estrictamente prohibida. Esta comunicacion es solo para propositos de informacion y no debe ser considerada como propuesta, aceptacion ni como una declaracion de voluntad oficial de REPSOL YPF S.A. y/o subsidiarias y/o afiliadas. La transmision de e-mails no garantiza que el correo electronico sea seguro o libre de error. Por consiguiente, no manifestamos que esta informacion sea completa o precisa. Toda informacion esta sujeta a alterarse sin previo aviso. This information is private and confidential and intended for the recipient only. 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When the conmnection hang, are all clients are affecte dat the same time ? Or is the problem punctual , ie, one client is affetcd now, then a different client the next time and so on? What is the status of the corresponding Informix session when it get hung - onstat -g ses <sid> (to get the <sid> type onstat -g ses (without an additional argument an search for the hung process' PID) What is verison your client connect libraries? Regards Tilman -- Tilman Model-Bosch IBM Data Managment Solutions, Informix Advanced Support c\\\\o SAP AG TECHDEV 05 Neurrotstr.16 69190 Walldorf forum.subscriber@iiug.org wrote on 18/04/2005 16:12:34: > You might have tried all the below, if not > 1. What is the status of the engine "onstat - ". Is it online or is it > in Blocked CKPT state. Might be it is waiting on a check point. > 2. What is the status of each session "onstat -u ", third column flags. > The first character/flag would tell you the status of the session. You > can get the explanation for each status from the manuals. It could be > C/Y/-. > 3. Have you tried onstat -g ntu. It tells you about the threads. > 4. onstat -g act. This tells you whether a thread is running. If you > don't see them moving, then that session/thread could be loading your > CPU. > 5. onstat -g wai. This tells you the threads that are waiting. > 6. When it hangs, do you recycle the instance. Try getting some > statistics. "Onstat -a" could take some time and space. > > > Thank you, > Kannan Thirugnanam > > -----Original Message----- > From: forum.subscriber@iiug.org [mailto:forum.subscriber@iiug.org] On > Behalf Of Murray Wood.... > Sent: Sunday, April 17, 2005 6:21 PM > To: ids@iiug.org > Subject: RE: Connections hang [4730] > > Can you reproduce the problem? You could start by determining what is > happening to the session when the process is hung. That will tell you > whether it is trying to do something in the engine or point you in > another > direction. > You cold also run the application with set explain on to determine > whether > one sql is poor or whether you have too many sqls for your server to > handle > in a reasonable time. > > MW > > > -----Original Message----- > > From: forum.subscriber@iiug.org > > [mailto:forum.subscriber@iiug.org] On Behalf Of ESTEBAN RIEZNIK > > Sent: Saturday, 16 April 2005 7:21 a.m. > > To: ids@iiug.org > > Subject: Connections hang [4728] > > > > Hi fellows, > > > > from time to time, not quite often but believe me its pretty > > annoying, happens that connections from remote servers or > > applications - every onsoctcp connections - to our main IDS > > box just hang without any apparent reason. Anyways local > > connections (e.g. a simple "dbaccess my_database") work fine! > > > > What parameters onconfig should i check or tune? Any onstat option? > > > > NETTYPE is set to soctcp,2,100,NET, all logical logs are > > backed up, there is plenty of swap space (for the OS as well > > as for informix TMP dbspaces), CPU is mostly idle, eliminated > > most busy sessions and some more at random pick from "onstat > > -u" to reduce their number, chache ratios are OK, locks are > > at normal level, network is working OK at full speed. Up to > > now, sincerely do not know what else to check. > > > > The box is IDS 9.40 on RedHat 7.3. > > > > Any help is really welcome > > > > > > > > > > > > >