HTTP3360: connection limit (xxx) exceeded in iplanet

Where xxx is the queue-size limit for the maximum number of concurrent HTTP connections that can be queued waiting for processing.

The server may also experience a hang or performance slowdown when receiving the HTTPP3360:connection limit (xxx)exceeded

What does the HTTP3360 error mean?

The connection limit is the same thing as the maximum number of threads that are set in the Connection Queue for incoming HTTP requests to be queued waiting for servicing. This is configurable via the thread-pool subelement queue-size via the server.xml configuration file

What is the Connection Limit?

The connection limit is the maximum number of ready connections that can be stored in the Connection Queue for incoming HTTP requests to be queued waiting to be serviced by a worker thread. This connection limit is configurable via the server.xml element thread-pool and its subelement queue-size .

In Oracle iPlanet Web Server 7.0 however, there is not a set default value for queue-size. The queue-size value is determined by the web servers auto-tune algorithm.


Since Web Server 7.0u2, the web server has been enhanced to automatically size the connection queue size and other server variables based on the number of file descriptors that are set on the operating system. The other variables affected by the auto detect feature is the keep-alive maximum number of connections and the maximum files for the file cache. The purpose of this enhancement is to allow the server to maximize and properly partition the file descriptors among the web server subsystems for maximum performance.
Possible Causes :

Here are some possible causes of the "Connection Limit (xxx) exceeded" message:

1. The connection queue limits may be reached as a result of an under tuned web server where the file descriptor limits have not been set for optimal server performance. In this case, we recommend sizing studies be done to determine what is the optimal thread settings to be set on the web server.

2. There may be slow response times from a specific application running on the web server which might result in incoming connections queue up. Eventually, the server reaches a point where all threads on the server are occupied and processing requests a full hang condition occurs.

3. For Web Server versions prior to 7.0u7, there was an auto-tuning bug which would auto tune the queue-size to 1.