TCP Channel tunning

You might want to tune TCP Channel related settings if say your backend is slow and the CPU is unused. In the Tunning Transport Channel service, we covered the basics of what is channel service. In that page click on the TCP Inbound Channel link and you will get this page

The most important setting on this page is the thread pool assigned to the channel. Each TCP transport channel is assigned to a particular thread pool. Thread pools can be shared between one or more TCP transport channels as well as with other components. The default settings for a TCP transport channel is to have all HTTP based traffic assigned to the WebContainer thread pool and all other traffic assigned to the Default thread pool.

Tune the size of your thread pools. By default, a thread pool can have a minimum of 10 threads and a maximum of 50 maximum threads. To adjust these values, click on Thread pools < threadpool_name and adjust the values specified for the Minimum Size and Maximum Size parameters for that thread pool. Typical applications usually do not need more than 10 threads per processor. One exception is if there is some off server condition, such as a very slow backend request, that causes a server thread to wait for the backend request to complete. In such a case, CPU usage is usually low and increasing the workload does not increase CPU throughput. Thread dumps show nearly all threads in a call out to the backend resource. If this condition exists, and the backend is tuned correctly, try increasing the minimum number of threads in the pooll until you see improvements in throughput and thread dumps show threads in other areas of the runtime besides the backend call. The setting for the Grow as needed parameter should not be changed unless your backend is prone to hanging for long periods of time. This condition might indicate that all of your runtime threads are blocked waiting for the backend instead of processing other work that does not involve the hung backend

Leave the Maximum open connections parameter set to the default value. This parameter controls the maximum number of connections that are available for a server’s use. It should be left at the default value of 20000, which is the maximum number of connections allowed

1 comment:

Anonymous said...


I am having issues in our prd servers, when our servers go down i am seeing this error in PTT tool,the error is " Used pool size of TCPChannel.DCS thread pool reach to 90% of its max size" this message keep repeating like 5 or 6 times and then server is restarting, the setting for TCPChannel are min 5 max 25, webcontainer settings are min 100, max 200. i need help immediately, these are prod servers.