Re: Threads Backload
Hallvard B Furuseth wrote: Bill MacAllister writes: In looking at some load issues on our servers we have starting recording some cn=Monitor counters for analysis. In particular we would like to understand what cn=Backload,cn=Threads,cn=Monitor contains. On our servers we have threads set to 8 and we have seen maximum backload values of 56. Does this means there are 56 connections waiting for an execution thread? Someone else could give a better answer but... No, it's the number of unfinished tasks submitted to the thread pool. Each LDAP operation is submitted as a separate task - i.e. a C function call to be performed. With your numbers, 8 or fewer are active and the remaining 48 are waiting for a thread to pick them up and run them. Note that some other tasks are also submitted to the thread pool, I don't remember quite which ones. Listening for new connections, reading from and closing a connection, depending on how slapd is compiled. "Run queue" tasks, which I don't remember what are. Replication, maybe. Note that in 2.4 a description appears for each thread related monitor entry. The one for backload states "Number of active plus pending threads", which is as much as I could infer from the formula that computes the return value for the call that computes the monitored value. p. Ing. Pierangelo Masarati OpenLDAP Core Team SysNet s.r.l. via Dossi, 8 - 27100 Pavia - ITALIA http://www.sys-net.it --- Office: +39 02 23998309 Mobile: +39 333 4963172 Fax: +39 0382 476497 Email: [email protected] ---
Re: Threads Backload
Bill MacAllister writes: > In looking at some load issues on our servers we have starting recording > some cn=Monitor counters for analysis. In particular we would like to > understand what cn=Backload,cn=Threads,cn=Monitor contains. On our servers > we have threads set to 8 and we have seen maximum backload values of 56. > Does this means there are 56 connections waiting for an execution thread? Someone else could give a better answer but... No, it's the number of unfinished tasks submitted to the thread pool. Each LDAP operation is submitted as a separate task - i.e. a C function call to be performed. With your numbers, 8 or fewer are active and the remaining 48 are waiting for a thread to pick them up and run them. Note that some other tasks are also submitted to the thread pool, I don't remember quite which ones. Listening for new connections, reading from and closing a connection, depending on how slapd is compiled. "Run queue" tasks, which I don't remember what are. Replication, maybe. -- Hallvard
Threads Backload
In looking at some load issues on our servers we have starting recording some cn=Monitor counters for analysis. In particular we would like to understand what cn=Backload,cn=Threads,cn=Monitor contains. On our servers we have threads set to 8 and we have seen maximum backload values of 56. Does this means there are 56 connections waiting for an execution thread? Bill + | Bill MacAllister | Systems Software Programmer, ITS Unix Systems, Stanford University
