As of Apache 2.1, the ability to use pooled connections to a backend server is available. Using the key=value parameters it is possible to tune this connection pooling. The default for a Hard Maximum for the number of connections is the number of threads per process in the active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM it is controlled by the ThreadsPerChild.
Setting min will determine how many connections will always be open to the backend server. Upto the Soft Maximum or smax number of connections will be created on demand. Any connections above smax are subject to a time to live or ttl. Apache will never create more than the Hard Maximum or max connections to the backend server.
Minumum number of connections that will always be open to the backend server.
max
1...n
Hard Maximum number of connections that will be allowed to the backend server. The default for a Hard Maximum for the number of connections is the number of threads per process in the active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM it is controlled by the ThreadsPerChild. Apache will never create more than the Hard Maximum connections to the backend server.
smax
max
Upto the Soft Maximum number of connections will be created on demand. Any connections above smax are subject to a time to live or ttl.
ttl
-
Time To Live for the inactive connections above the smax connections in seconds. Apache will close all connections that has not been used inside that time period.
timeout
Timeout
Connection timeout in seconds. If not set the Apache will wait until the free connection is available. This directive is used for limiting the number of connections to the backend server together with max parameter.
