Patrick Buchinger wrote: > i have sapdb 7.3.24 running on red hat 7.2. let's call this > machine db. > on a second red hat 7.2 machine i have jboss 2.4.4 running. let's call > this machine web. > > ok, jboss running on web connects to the database running on db. the > network connection between both machines is fast enough (connected > through 2 extra ethernet adapters which only handle this connection). > > the whole thing runs quite stable, except we have heavy load on jboss > (and thus on the database). on heavy load, jboss prints a lot of > > "[11:23:10,310,TxCapsule] Transaction XidImpl [FormatId=257, > GlobalId=web//44389, BranchQual=] timed out. status=STATUS_ACTIVE" > > messages into its log and after some minute jboss cannot recieve any > data from the database anymore. a restart of jboss solves the problem, > everything works fine after that. > > the above mentioned error message looks like there are many > connections > between jboss and database, and the database is not able to > process all > these connections within a specified time. thus, the transactions > started by jboss time out and produce these error messages. could this > be right? > > so i think the problem might be the database, which is not able to > handle the queries fast enough. > > i took a look at the memory usage of the database and found > out, that it > does not use very much memory (aprox. 132mb, if i correctly interpret > top's output). since the server has 2gb of memory, the > databas could use > much more memory. > > so, my questions are: > * could the usage of this little memory be (part of) our performance > problem? > * if so --> how can i tell the database to use more memory?
You should increase the database parameter DATA_CACHE. It's calculated in 8KB pages. So a value of 200000 could be a good value for your database. This will increase the amount of memory which is used to cache database pages. Kind regards, Holger SAP Labs Berlin -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
