Java virtual machine tuning  Operating system settings

Chapter 2: Server Tuning

Listener tuning

EAServer includes several preconfigured listeners, described in “Preconfigured listeners” in the EAServer System Administration Guide. Remove any listeners that you do not need. For example, if your application does not need to support MASP or Open Server clients, remove these listeners. Unused listeners waste memory and network resources.

The following listener properties affect performance:

Property

EAServer Manager location

Full name

Keep alive HTTP only

Listener Properties/Advanced/ Keep alive

com.sybase.jaguar.listener.http.conn.keepalive

Maximum requests HTTP only

Listener Properties/Advanced/ Maximum Requests

com.sybase.jaguar.listener.http.conn.maxrequests

Request pool size Solaris platform only

Listener Properties/Advanced/ Request Pool Size

com.sybase.jaguar.listener.solaris.tli.maxoutcon

For listeners that use the SSL protocol, you can tune the SSL session caching parameters described in “SSL session caching”.


HTTP keep alive

This setting determines how long the server keeps idle HTTP connections open. The same browser client may send several requests at periodic intervals, for example, if the user is browsing linked documents or paging through consecutive forms. In these cases, there is a performance benefit if the connection remains open, since it takes time to reestablish a new connection. The default value is 100 seconds. To change the setting, enter a different time in seconds.


HTTP maximum requests

This setting specifies the maximum number of HTTP requests to service before closing each connection. The default is 100. Tuning the value provides a way to prevent clients from monopolizing HTTP threads and connections with a series of short-duration requests.


Connection request pool size

On Solaris, you can configure the size of the pool used to handle outstanding connection requests. When the server is very busy, all available threads may be in use when a connect request arrives. These pending connect requests are pooled until they can be handled. If the pool size is too small, client connection requests may time out before the server can handle the request.

You can configure different request pool sizes for different protocols. For example, if the server is handling mostly HTTP requests, you can increase the request pool size for the HTTP listener while leaving the IIOP request pool size at a low value.

Values must be a positive integer less than or equal to 4096. If this property is not set, the default is 128. Values greater than 4096 are truncated to 4096 to avoid excessive memory allocation at start-up.

The connection request pool size affects the server memory requirements:

mem = entries * 20K

That is, each entry requires about 20K of memory reserved at server start-up.


SSL session caching

For improved performance, EAServer caches SSL session identifiers and allows clients to reuse them. Since creating an SSL session requires CPU-intensive computations, SSL session reuse results in a relatively large performance gain over setting up completely new security sessions for each connection. The SSL settings for a listener are configured in the security profile set in the listener Security Profile property (if using jagtool, the property com.sybase.jaguar.listener.security). For details on creating security profiles, see “Configuring security profiles” in Chapter 13, “Security Configuration Tasks,” in the EAServer Security Administration and Programming Guide.

The settings below, on the Advanced tab in the EAServer Manager Security Profile Properties dialog box, control how SSL clients can reuse sessions for subsequent and simultaneous connections.

Setting

Description

SSL Cache Size

The number of entries in SSL session cache. If using jagtool, set as security profile property com.sybase.jaguar.security.sesscachesize.

SSL Session Share

The number of concurrent connections that can simultaneously use the same session entry (ID) in the session cache. If using jagtool, set as security profile property com.sybase.jaguar.security.sessshare.

SSL Session Linger

The duration for which a session entry is kept in the SSL session cache after the last SSL session using this session ID was closed. If using jagtool, set as security profile property com.sybase.jaguar.security.cachetime.

Cached sessions allow the client to reuse a session in a subsequent connection. The SSL Cache Size setting controls how many entries can be cached. Set this to a number less than or equal to the maximum connections setting for the server. The default cache size for security profiles created in EAServer Manager is 30. The cache requires approximately 64 bytes per entry. The SSL Session Linger value specifies how long cached session IDs remain valid. The default is 8 hours.

The SSL Session Share setting specifies how many simultaneous connections can share one session ID. Session sharing can improve performance when the client opens multiple connections simultaneously. For example, a browser client may open several connections at once to download images linked to an HTML page. Session sharing allows the client to reuse the session for the second and subsequent connections, up to the number of concurrent connections specified by the SSL Session Share value. The default value is 10.

NoteThese are advanced SSL parameters. They should be set only by someone who is knowledgeable about SSL.





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