You can tune security to balance performance with function.
You can achieve this balance following considerations for tuning general
security, Common Secure Interoperability version 2 (CSIv2), Lightweight
Directory Access Protocol (LDAP) authentication, Web authentication,
and authorization.
About this task
Performance issues typically involve trade-offs between function
and speed. Usually, the more function and the more processing that
are involved, the slower the performance. Consider what type of security
is necessary and what you can disable in your environment. For example,
if your application servers are running in a Virtual Private Network
(VPN), consider whether you can disable Secure Sockets Layer (SSL).
If you have a lot of users, can they be mapped to groups and then
associated to your Java 2 Platform, Enterprise Edition (J2EE) roles?
These questions are things to consider when designing your security
infrastructure.
Procedure
- Consider the following recommendations for tuning general
security.
- Consider disabling Java 2 security manager if you know exactly
what code is put onto your server and you do not need to protect process
resources. Remember that in doing so, you put your local resources
at some risk.
- Consider
propagating new security settings to all nodes before restarting the
deployment manager and node agents, to change the new security policy.
If
your security configurations are not consistent across all servers,
you get access denied errors. Therefore, you must propagate new security
settings when enabling or disabling global security.
Configuration
changes are generally propagated using configuration synchronization.
If auto-synchronization is enabled, you can wait for the automatic
synchronization interval to pass, or you can force synchronization
before the synchronization interval expires. If you are using manual
synchronization, you must synchronize all the nodes.
If the
cell is in a configuration state and the security policy is mixed
with nodes that have security enabled and disabled, you can use the
syncNode utility to synchronize the nodes where the new settings are
not propagated.
For more detailed information about enabling
security in a distributed environment, see Enabling security for the realm.
- Consider increasing the cache and token timeout if you feel your
environment is secure enough. By increasing these values, you have
to re-authenticate less often. This action supports subsequent requests
to reuse the credentials that already are created. The downside of
increasing the token timeout is the exposure of having a token hacked
and providing the hacker more time to hack into the system before
the token expires. You can use security cache properties to determine
the initial size of the primary and secondary hashtable caches, which
affect the frequency of rehashing and the distribution of the hash
algorithms.
See
the article Security cache properties for a list of
these properties.
- Consider changing your administrative connector from Simple Object
Access Protocol (SOAP) to Remote Method Invocation (RMI) because RMI
uses stateful connections while SOAP is completely stateless. Run
a benchmark to determine if the performance is improved in your environment.
- Use the wsadmin script to complete the access IDs for all the
users and groups to speed up the application startup. Complete this
action if applications contain many users or groups, or if applications
are stopped and started frequently. WebSphere Application Server maps
user and group names to unique access IDs in the authorization table.
The exact format of the access ID depends on the repository. The
access ID can only be determined during and after application deployment.
Authorization tables created during assembly time do not have the
proper access IDs. See Commands for the AdminApp object for
more information about how to update access IDs.
Consider tuning the Object Request Broker
(ORB) because it is a factor in enterprise bean performance with or
without security enabled. Refer to the ORB tuning guidelines topic.
- If using SSL, enable the SSL session tracking mechanism option
as described in the article, Session management settings.
In some cases, using the unrestricted
Java Cryptography Extension (JCE) policy file can improve performance.
Refer to the article, Tuning
Web services security.
- Consider the following steps to tune Common
Secure Interoperability version 2 (CSIv2).
- Consider using Secure Sockets Layer (SSL) client certificates
instead of a user ID and password to authenticate Java clients. Because
you are already making the SSL connection, using mutual authentication
adds little overhead while it removes the service context that contains
the user ID and password completely.
- If you send a large amount of data that is not very security sensitive,
reduce the strength of your ciphers. The more data you have to bulk
encrypt and the stronger the cipher, the longer this action takes.
If the data is not sensitive, do not waste your processing with 128-bit
ciphers.
- Consider putting only an asterisk (*) in the trusted server ID
list (meaning trust all servers) when you use identity assertion for
downstream delegation. Use SSL mutual authentication between servers
to provide this trust. Adding this extra step in the SSL handshake
performs better than having to fully authenticate the upstream server
and check the trusted list. When an asterisk (*) is used, the identity
token is trusted. The SSL connection trusts the server through client
certificate authentication.
- Ensure that stateful sessions are enabled for CSIv2. This is the
default, but requires authentication only on the first request and
on any subsequent token expirations.
You can
further enhance performance by optimizing the values for the CSIv2
session cache. For more information on these settings, see the following
custom properties in the Security custom properties topic:
- com.ibm.websphere.security.util.csiv2SessionCacheLimitEnabled
- com.ibm.websphere.security.util.csiv2SessionCacheIdleTime
- com.ibm.websphere.security.util.csiv2SessionCacheMaxSize
- If you are communicating only with WebSphere
Application Server Version 5 or higher servers, make the Active Authentication
Protocol CSI, instead of CSI and SAS. This action removes an interceptor
invocation for every request on both the client and server sides.
If you are communicating only with WebSphere
Application Server Version 5 or higher servers, make the Active Authentication
Protocol CSI, instead of CSI and SAS. This action removes an interceptor
invocation for every request on both the client and server sides. Important:
For a pure Java
client, you can disable the creation of server sockets used for Object
Request Broker (ORB) callbacks. Do this step only if you are communicating
with servers running WebSphere Application Server, Version 5 or later.
- In the sas.client.props file, add com.ibm.CSI.claimTransportAssocSSLTLSRequired=false and com.ibm.CSI.claimTransportAssocSSLTLSSupported=false.
- Set the active protocol to csiv2 instead of both in
the sas.client.props file.
The protocol property changes
to com.ibm.CSI.protocol=csiv2.
- Consider the following steps to tune Lightweight
Directory Access Protocol (LDAP) authentication.
- In the administration console,
click Security > Global Security.
- Under User registries, click LDAP.
- Select the Ignore case for
authorization option in the WebSphere Application Server LDAP
User Registry configuration, when case-sensitivity is not important.
- Select the Reuse connection option.
- Use the cache features that your LDAP server supports.
- Choose either the IBM Tivoli Directory Server or SecureWay
directory type, if you are using an IBM Tivoli Directory Server. The
IBM Tivoli Directory Server yields improved performance because it
is programmed to use the new group membership attributes to improve
group membership searches. However, authorization must be case insensitive
to use IBM Tivoli Directory Server.
- Choose either iPlanet Directory Server (also known as
Sun ONE) or Netscape as the directory if you are an iPlanet Directory
user. Using the iPlanet Directory Server directory can increase performance
in group membership lookup. However, use Role only for group
mechanisms.
- Consider the following steps to tune
Web authentication.
- Consider the following steps to tune authorization.
- Map your users to groups in the user registry. Associate the groups
with your Java 2 Platform, Enterprise Edition (J2EE) roles. This association
greatly improves performance when the number of users increases.
- Judiciously assign method-permissions for enterprise beans. For
example, you can use an asterisk (*) to indicate all the methods in
the method-name element. When all the methods in enterprise beans
require the same permission, use an asterisk (*) for the method-name
to indicate all methods. This indication reduces the size of deployment
descriptors and reduces the memory that is required to load the deployment
descriptor. It also reduces the search time during method-permission
match for the enterprise beans method.
- Judiciously assign security-constraints for servlets. For example,
you can use the *.jsp URL pattern to apply the same authentication
data constraints to indicate all JavaServer Pages (JSP) files. For
a given URL, the exact match in the deployment descriptor takes precedence
over the longest path match. Use the *.jsp, *.do, *.html extension
match if no exact matches exist and longest path matches exist for
a given URL in the security constraints.
Results
You always have a trade off between performance, feature,
and security. Security typically adds more processing time to your
requests, but for a good reason. Not all security features are required
in your environment. When you decide to tune security, create a benchmark
before making any change to ensure that the change is improving performance.
What to do next
In a large scale deployment, performance is very important.
Running benchmark measurements with different combinations of features
can help you to determine the best performance versus the benefit
of configuration for your environment. Continue to run benchmarks
if anything changes in your environment, to help determine the impact
of these changes.