The <ESB_Home>/repository/conf/passthru-http.properties file contains tuning parameters related to the HTTP Pass Through transport. This is the default transport of the WSO2 ESB since it optimises the performance of the ESB in most scenarios. The performance can be further optimised when this transport is used with header based routing or smaller sized messages.
These parameters can be modified as required based on your production environment. This information is provided as a reference for users who are already familiar with the product features and want to know how to configure them.
Pass-through HTTP transport specific tuning parameters
| Parameter Name | Description | Default Value |
|---|---|---|
| worker_pool_size_core | Initial number of threads in the worker thread pool. This can be increased to match an increased number of messages to be processed until the value specified for the worker_pool_size_max parameter is reached. | 400 |
| worker_pool_size_max | Maximum number of threads in the worker thread pool. Specifying a maximum limit helps to avoid performance degradation that can occur due to context switching. If you get the error | 500 |
| http.socket.timeout | Maximum period of inactivity between two consecutive data packets. Given in milliseconds. | 120000 |
| worker_thread_keepalive_sec | Defines the keep-alive time for extra threads in the worker pool. This should be less than the socket timeout. Once this time has elapsed for an extra thread, it will be destroyed. The purpose of this parameter is to optimise the usage of resources by avoiding wastage that results from having unutilized extra threads. | 60 |
| worker_pool_queue_length | Defines the length of the queue that is used to hold runnable tasks to be executed by the worker pool. The thread pool starts queuing jobs when all the existing threads are busy and the pool has reached the maximum number of threads. The value for this parameter should be -1 to use an unbounded queue. If a bound queue is used and the queue gets filled to its capacity, any further attempts to submit jobs will fail causing some messages to be dropped by Synapse. | -1 |
| io_threads_per_reactor | Defines the number of IO dispatcher threads used per reactor. The value for this property should not exceed the number of cores in the server. | 2 |
| io_buffer_size | Size in bytes of the buffer through which data passes. | 16384 |
| http.max.connection.per.host.port | Defines the maximum number of connections allowed per host port. | 32767 |
| http.socket.reuseaddr | If this parameter is set to true, it is possible to open another socket on the same port as that of the socket which is currently used by the ESB server to listen to connections. This is useful when recovering from a crash. On such occasions, if the socket is not properly closed, a new socket can be opened in order to continue with the listening. | true |
| http.socket.buffer-size | This is used to configure the | 8192 |
Other parameters
| Parameter Name | Description | Default Value |
|---|---|---|
| http.block_service_list | If this parameter is set to true, all the services deployed to the WSO2 ESB cannot be accessed from the http(s):<esb>:8280/services/ URL. | true |
| http.origin-server | This parameter is used to customize the name of the origin server in the HTTP response header. | |
| http.user.agent.preserve | If this parameter is set to true,the User-Agent HTTP header of messages passing through the ESB will be preserved and printed in the outgoing message. | false |
| http.server.preserve | If this parameter is set to true, Server HTTP header of messages passing through the ESB will be preserved and printed in the outgoing message. | false |
| http.connection.disable.keepalive | If this parameter is set to true, the HTTP connections with the back end service will be closed soon after the request is served. It is recommended to set this property to false so that the ESB does not have to create a new connection every time it sends a request to a back end service. However, you may need to close connections after they are used if the back end service does not provide sufficient support for keep alive connections. | false |
| rest.dispatcher.service | This parameter determines how requests from clients to the ESB are dispatched to the REST APIs of the ESB. The MultitenantDispatcherService which is selected by default for this parameter dispatches requests from multiple clients at a given time. | MultitenantDispatcherService |
Example
The following example shows excerpts from a passthru-http.properties file.
## This file contains the configuration parameters used by the Pass-through HTTP transport ## Pass-through HTTP transport specific tuning parameters worker_pool_size_core=400 worker_pool_size_max=500 #worker_thread_keepalive_sec=60 #worker_pool_queue_length=-1 #io_threads_per_reactor=2 io_buffer_size=16384 #http.max.connection.per.host.port=32767 # This property is crucial for automated tests http.socket.reuseaddr=true ## Other parameters http.block_service_list=true #http.user.agent.preserve=false #http.server.preserve=true #http.connection.disable.keepalive=false rest.dispatcher.service=__MultitenantDispatcherService