IBM Support

Integrated awareness on Notes 6.5.x results in server outages

Technote (FAQ)


Question

Interaction between Lotus Notes Client 6.5.x Instant Messaging (IM) and a Lotus Sametime server may cause the CPU to spike on both the Sametime server and the Notes client (nlnotes process).

Symptoms of this problem can include:

  • The nlnotes process on the Notes client spikes to 100%. Logging off from Notes client IM returns the CPU on the nlnotes process to normal.
  • The CPU on multiple processes on the Sametime server are pegged at above normal rates that may eventually reach 100%.
  • Attempting to open a chat session with another client shows the message "Initializing chat: Resolving User Name". This is an organization-wide outage.
  • Attempting to add someone to a contact list will take an inordinate amount of time
  • On iSeries this problem will appear as an abnormal termination of the StMux task. You would probably not notice a CPU spike because the CPU has so much processing power available.

Answer

These problems are caused by the resolve and awareness requests that are generated by the Notes client to provide awareness with the Sametime server.



Correcting the problem

To correct these problems, administrators should do the following:


1.
Verify that the Sametime server is running Fix Pack 1 (FP1) for Sametime 6.5.1 or is running Sametime version 7.0.

2. Upgrade the Notes clients to the latest CCH for 6.5.4, the latest CCH for 6.5.5 or 7.0.1. Moving to these releases includes a number of enhancements which reduce the Sametime server load that is driven by Notes IM. These new features are integrated with fundamental architectural enhancements to Notes IM capabilities and cannot be retrofitted into earlier versions of Notes 6.5.x. The new features include:

  • Maintaining a "resolve request cache" of every unique name from any view or document that the user looked at throughout the course of the day. This feature avoids redundant resolve requests; however, as noted above, this cache does not (at the writing of this document) persist between Notes instances.
  • Maintaining a "watch list" size of 500 users. This feature limits the virtual contact list of Notes to a maximum of 500 most recent unique names, while minimizing memory consumption on the Notes client.
  • Bundling name resolve requests to the Sametime server. This feature combines the unique names found in a view or document to a single request, reducing the number of requests that a Notes client will make to the Sametime server.
  • Correcting a problem where Notes IM gets into a looping state that floods the Sametime server with large numbers of requests. See Technote #1229576 for details.


3.
Administrators are strongly advised to use the two options below to disable public group expansion and improve the efficiency of their Domino name lookup cache.

What to do Why Details
Option 1:
Disable public group expansion for Notes IM
Disabled means that the Notes client will not send resolve requests for public groups.

This eliminates the concern that user(s) could send a large public group to the server which, when expanded, could generate thousands of resolve requests. This could slow down or overwhelm the Sametime server.

In larger enterprises, it is recommended that public group expansion be disabled for Notes IM.

This setting does not affect the public groups included in the users' IM contact lists; it affects only public groups listed in the To: or CC: fields of mail documents.

When not disabled (set to 0), public groups would expand and be included in the IM contact list for the time the user is working with that document.

Set the following notes.ini variable on each Notes client:. This setting can be issued using a desktop policy. For more information, refer to the document "The desktop policy in the Domino Directory can be designed to set notes.ini and Location parameters" (#1196837).

IM_WATCH_PUBLIC_GROUPS=0

This option is only available on Notes 6.5.4 CCH4 clients and higher.

Option 2:
Increase the Domino server name lookup cache

(for Sametime servers configured with a Domino directory only)
The NameLookupCache reduces Domino server load driven by resolve requests from Sametime clients, including Notes IM. Resolve requests in this server configuration ultimately become Domino NameLookups. Provisioning an appropriate cache size enables Domino to minimize actual directory queries. Set the notes.ini parameter NLCACHE_SIZE equal to the number of bytes you want the maximum cache size to be.

Example:
NLCACHE_SIZE=67108864

For optimal performance, the size of this cache needs to exceed the maximum that will occur under normal situations. Any additional memory will not be used (nor will it "cost" anything). IBM recommends a Domino NAMELookup cache size of 64 MB for Sametime server configurations.

To show database.namelookup stats enter the following on the Domino console:

show stat database.namelookup*

To determine if your NameLookupCache is large enough, compare:
Database.NAMELookupCacheMaxSize
with:
Database.NAMELookupCachePool.Peak and Database.NAMELookupCachePool.Used.

Neither value should have reached Database.NAMELookupCacheMaxSize

If the numbers are close, increase the cache size.

Refer to the Name lookup cache testing section of this developerWorks article for additional insight into setting NAMELookup cache.

If system administrators do not want to examine the statistics on their system to tune the cache size (which is a trial and error process by nature), performance testing done in the Domino 6.x timeframe suggests that a 64 MB (67108864) setting would likely be adequate for most systems, and can be considered an adequate setting for Sametime servers (with tuning occurring if Database.NAMELookupCachePool.Peak becomes equal to Database.NAMELookupCacheMaxSize.)

Workaround:
If you are unable to upgrade the Notes Clients and make the two additional modifications above, administrators can use one or more of the options below to minimize the load that Notes IM is placing on the Sametime server.

What to do Why Details
Disable Notes IM by policy The Notes client will behave as if no Sametime server is set in the Location document's Sametime server field.

When a user has this ini variable enabled, any impact the Notes client would have on the Sametime server is eliminated.

Set the IM_Disabled=1 in the users' notes.ini files. Refer to technote #1117272 for additional information.
Configure Notes to not log on automatically Tends to substantially smooth the server load driven by Notes IM users, by extending the period until the user base achieves steady state resolve request caches. In the users' Location document(s), under the Instant Messaging tab - Connect: option, select Manually. This will require the user to initiate logon to the Sametime server either via the status bar's IM control or by selecting File -> Instant Messaging -> Log On Instant Messaging. This option may also be configured via Policies (see below).
Disable awareness within views and documents This will turn off IM status for names in documents and views, This eliminates resolve requests for those names, while still allowing chat and awareness functionality within a user's IM contact list. There are two three ways to disable this:

1. From the Notes client, select File -> Preferences -> User Preferences -> Instant Messaging -> Uncheck "Show Instant Messaging Status for Names."
2. Edit the Notes.ini on the client and set the following parameter to 0:
IM_SHOW_STATUS=0
The Notes client must be restarted for this change to take effect.

3. Use Desktop Policies to push down the notes.ini parameter to the client.

Related information

Notes Instant Messaging displays several public groups
How to determine the Client Type that is connecting to


    Cross reference information
    Segment Product Component Platform Version Edition
    Messaging Applications Lotus End of Support Products Lotus Sametime AIX, i5/OS, Solaris, Windows 7.0, 6.5.1

Document information

More support for: Lotus End of Support Products
Lotus Notes

Software version: 6.5.2, 6.5.3, 6.5.4

Operating system(s): Windows

Reference #: 1206369

Modified date: 25 January 2008


Translate this page: