Technote Number: 1202023
Problem:
This issue was reported to Quality Engineering as SPR#LBRD5TVRV, and was fixed
in Domino 6.5.4 Fix Pack 2.
Excerpt from the Lotus Domino Release 6.5.4 Fix Pack 2 fix list (available at
http://www.ibm.com/developerworks/lotus):
Compact
SPR# LBRD5TVRVF - Performance improvement when using Compact on medium and
large databases, on the Unix platform.
There are now new options that can be used to avoid these problems.
1. Using the "in-place" option with the compact task (-Q or -q) will prevent
it from using the cache during its run. NOTE: For Domino servers running on
Solaris or AIX, this procedure can be used on any database as described. Due
to the design of the Windows architecture, in order for the no-cache option to
be used, the database must not be open. If the -Q or -q option is run against
an open database in Windows - e.g. the server's Domino Directory - then a
standard compact would be performed, and the option ignored.
2. A new NOTES.INI parameter has been introduced to regulate file system cache
behavior: DEBUG_FileSizeThreshold=[file size in MB]. This parameter mandates
that any database larger than the specified size will be opened without using
the file system cache. Note that this can be enabled dynamically on the Domino
console, with no need to restart. While this circumvents the compact task
performance issue, be aware that this parameter causes all databases above the
limit to bypass the cache for all database operations. Depending on the server
configuration and databases used, this may cause an impact on database read
performance.
3. A new diagnostic parameter has also been included:
DEBUG_FileSyncThreshold=[time in ms]. Also a dynamic parameter, it is designed
to provide information in the event troubleshooting is necessary. In general,
this parameter should not be enabled unless Lotus Support requests its
activation.
Once enabled, these parameters can have a marked impact on compact
performance. The following chart illustrates tests performed on sample
databases with compact. Note that these times are for comparison purposes
only. The contents of the database and the hardware capabilities of the Domino
system performing the compact can cause variations in performance.
Operating System
WIN32
SOLARIS
AIX
compact time 20MB
00:01:36
00:01:15
00:00:28
NEW compact time 20MB
00:01:51
00:00:26
00:00:15
compact time 500MB
00:33:39
01:02:04
01:43:10
NEW compact time 500MB
00:27:56
00:20:34
01:21:51
compact time 1GB
01:25:04
03:38:02
10:00:54
NEW compact time 1GB
00:48:33
00:50:07
NA
These new options are designed to optimize performance by bypassing the
standard caching mechanisms the server uses. There are also operating system
optimizations that can improve performance by improving buffer management. To
date, the main operating system to incorporate these optimizations is AIX;
version 5.3 has changes to the Logical Volume Manager that increases
performance and throughput on operations such as compact. The following sample
statistics show the benefits of compact performance under AIX 5.3.
Operating System
AIX 5.2
AIX 5.3
compact time 7.1 GB
05:47:00
3:41:00
Refer to the following document on the Upgrade Central site for details about
Lotus Domino 6.5.4 Fix Pack 2 (FP2), and how to obtain it:
Upgrade Central: Planning your upgrade to Lotus Notes/Domino 6.0.5 and 6.5.4,
Including Domino 6.5.4 Fix Pack 1 and Fix Pack 2 (# 1201845) More >
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