[Erp5-report] r26479 - /erp5/trunk/products/CMFActivity/Activity/SQLQueue.py

[nobody at svn.erp5.org]

Author: vincent
Date: Fri Apr 17 15:30:06 2009
New Revision: 26479

URL: http://svn.erp5.org?rev=26479&view=rev
Log:
Change SQLQueue's MESSAGE_BUNDLE_SIZE from 10 to 1. This matches "historical" behaviour, and is a safer value.

Modified:
    erp5/trunk/products/CMFActivity/Activity/SQLQueue.py

Modified: erp5/trunk/products/CMFActivity/Activity/SQLQueue.py
URL: http://svn.erp5.org/erp5/trunk/products/CMFActivity/Activity/SQLQueue.py?rev=26479&r1=26478&r2=26479&view=diff
==============================================================================
--- erp5/trunk/products/CMFActivity/Activity/SQLQueue.py [utf8] (original)
+++ erp5/trunk/products/CMFActivity/Activity/SQLQueue.py [utf8] Fri Apr 17 15:30:06 2009
@@ -54,7 +54,16 @@
 # Read this many messages to validate.
 READ_MESSAGE_LIMIT = 1000
 # Process this many messages in each dequeueMessage call.
-MESSAGE_BUNDLE_SIZE = 10
+# Downside of setting to a "small" value: the cost of reserving a batch of
+# few messages increases relatively to the cost of executing activities,
+# making CMFActivity overhead significant.
+# Downside of setting to a "big" value: if there are many slow activities in
+# a multi-activity-node environment, multiple slow activities will be reserved
+# by a single node, making a suboptimal use of the parallelisation offered by
+# the cluster.
+# Before increasing this value, consider using SQLDict with group methods
+# first.
+MESSAGE_BUNDLE_SIZE = 1
 
 class SQLQueue(RAMQueue, SQLBase):
   """