From afe8151d40060da16cab747ff1bede4d0ead405a Mon Sep 17 00:00:00 2001 From: Alejandro Revilla Date: Fri, 19 Sep 2014 10:13:43 -0300 Subject: [PATCH] TM properties --- doc/src/asciidoc/ch09/transaction_manager.asc | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/doc/src/asciidoc/ch09/transaction_manager.asc b/doc/src/asciidoc/ch09/transaction_manager.asc index 3384c86b13..b6fef8a59d 100644 --- a/doc/src/asciidoc/ch09/transaction_manager.asc +++ b/doc/src/asciidoc/ch09/transaction_manager.asc @@ -188,4 +188,31 @@ This adds the following information to the log ------------ +* *sessions* + +Defines the number of simultaneous sessions (Threads) used to process transactions. +Defaults to one. It is recommended to keep the `sessions` property with a +reasonable value commensurate the number of CPU cores of the system. A +large number here just slows down the capacity of the system. + +* *max-sessions* + +In order to deal with occasional traffic spikes (sometime caused by small +network glitches), the TransactionManager can temporarily increase the +number of sessions. This property defines that maximum. It defaults to +the value set for `sessions`. For obvious reasons, `max-sessions` can't +be less than `sessions`. + +* *max-active-sessions* + +When using the TransactionManager _continuations_ feature (prepare callback +returns `PAUSE` modifier), it is possible that a small number of sessions +can process a large number of in-flight transactions. Those transactions +may place in the `Context` references to live objects such as JDBC +sessions. In order to place a cap on the number of in-flight transactions +to avoid exhausting resources (for example a JDBC pool), this +`max-active-sessions` property can be set. The default is 0. + +[TIP] +===== +If you're _pausing_ your transactions, please read the previous paragraph +multiple times and make sure you understand it. +=====