Configuring nhttp.properties

The <ESB_HOME>/repository/conf/nhttp.properties file contains tuning parameters related to HTTP-NIO Transport. 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.

Parameters used by non-blocking HTTP-NIO transport

Parameter Name	Description	Default Value
`http.socket.timeout`	Maximum period of inactivity between two consecutive data packets. Given in milliseconds. This parameter is also defined as SO_TIMEOUT.	60000
http.socket.timeout.receiver	Maximum period of inactivity between two consecutive data packets for the transport listener side. This is the socket timeout value for connection between the client and the ESB server. The value is given in milliseconds.	60000
http.socket.timeout.sender	Maximum period of inactivity between two consecutive data packets for the transport sender side. This is the socket timeout value for connection between the ESB server and the backend server. The value is given in milliseconds.	60000
`nhttp_buffer_size`	The size of the buffer through which data passes when receiving/transmitting NHTTP requests. This is given in bytes.	8192
`http.tcp.nodelay`	This determines whether Nagle's algorithm (for improving the efficiency of TCP/IP by reducing the number of packets sent over the network) is used. Value 0 is used to enable this algorithm and value `1` is used to disable it. The algorithm should be enabled if you need to reduce bandwidth consumption.	1
`http.connection.stalecheck`	This determines whether stale connection check is used. Value 0 is used to enable stale connection check and value `1` is used to disable it. When this parameter is enabled, connections which are no longer used will be identified and disabled before each request execution. Stale connection check should be disabled when performing critical operations.	0

Properties for AIX based deployment

Parameter Name	Description	Default Value
`http.nio.interest-ops-queueing`	Determines whether interestOps() queueing is enabled for the I/O reactors.	`true`

HTTP Sender (Client Worker) thread pool parameters

The following parameters relate to worker thread pools that are used to process responses in non-blocking HTTP transport:

Parameter Name	Description	Default Value
lst_t_core	Initial number of threads in the response processing worker (Client Worker) pool. If the number of live threads is less than the value defined here, a new thread is created to process the response.	20
`lst_t_max`	Maximum number of threads in the response processing worker (Client Worker) pool. If the queue (`lst_qlen`) is full and the number of live threads is less that the value defined here, a new thread will be created to process the response.	100
`lst_alive_sec`	The keep-alive time in seconds for idle threads in the response processing worker pool. Once this time has elapsed for an idle thread, it will be destroyed. The purpose of this parameter is to optimize the usage of resources by avoiding wastage that results from having idle threads.	5
`lst_qlen`	The length of the queue that is used to hold runnable tasks to be executed by the response processing worker pool. If the number of live threads is equal to the core pool size (`lst_t_core`) and all threads are busy, new responses will be pushed into the queue so that they can be processed when a thread becomes available. If you need new threads to be created beyond the core pool size (`lst_t_core`), ensure you change the default value of this parameter so that it becomes a bounded queue If the queue is full, all threads are busy and the number of live threads is equal to the max pool size (`lst_t_max`), new responses will be rejected by the response processing worker.	-1
lst_io_threads	Sender-side IO workers.	2

When there is an increased load, it is recommended to increase the number of threads mentioned in the parameters above to balance it.

HTTP Listener thread pool parameters

The following parameters relate to worker thread pools that are used to process requests in non-blocking HTTP transport:

Listener-side parameters should generally have the same values as the sender-side parameters.

Parameter Name	Description	Default Value
snd_t_core	Initial number of threads in the worker thread pool. If the number of live threads is less than the value defined here, a new thread is created to process the request.	20
snd_t_max	Maximum number of threads in the request processing worker (Server Worker) pool. If the queue (snd`_qlen`) is full and the number of live threads is less that the value defined here, a new thread will be created to process the request.	100
snd_alive_sec	Keep-alive time in seconds for idle threads in the worker pool. Once this time has elapsed for an idle thread, it will be destroyed. The purpose of this parameter is to optimise the usage of resources by avoiding wastage that results from having idle threads.	5
snd_qlen	The length of the queue that is used to hold runnable tasks to be executed by the request processing worker pool. If the number of live threads is equal to the core pool size (`snd_t_core`) and all threads are busy, new requests will be pushed into the queue so that they can be processed when a thread becomes available. If you need new threads to be created beyond the core pool size (`snd_t_core`), ensure you change the default value of this parameter so that it becomes a bounded queue. If the queue is full, all threads are busy and the number of live threads is equal to the max pool size (`snd_t_max`), new requests will be rejected by the request processing worker.	-1
`snd_io_threads`	Listener-side IO workers.	2

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 viewed from the http(s):<esb>:8280/services/ URL.	`false`
`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.	`false`

Example

The following example shows excerpts from a nhttp.properties file.

#
#        http://www.apache.org/licenses/LICENSE-2.0
#
# This file contains the configuration parameters used by the Non-blocking HTTP transport
#http.socket.timeout=60000
#nhttp_buffer_size=8192
#http.tcp.nodelay=1
#http.connection.stalecheck=0
# Uncomment the following property for an AIX based deployment
#http.nio.interest-ops-queueing=true

# HTTP Listener thread pool parameters
#snd_t_core=20
#snd_t_max=100
#snd_alive_sec=5
#snd_qlen=-1
#snd_io_threads=2
# HTTP Sender thread pool parameters
#lst_t_core=20
#lst_t_max=100
#lst_alive_sec=5
#lst_qlen=-1
#lst_io_threads=2
nhttp.rest.dispatcher.service=__MultitenantDispatcherService
# URI configurations that determine if it requires custom rest dispatcher
rest_uri_api_regex=\\w+://.+:\\d+/t/.*|\\w+://.+\\w+/t/.*|^(/t/).*
rest_uri_proxy_regex=\\w+://.+:\\d+/services/t/.*|\\w+://.+\\w+/services/t/.*|^(/services/t/).*

For information on tuning performance of WSO2 ESB using these properties, see Performance Tuning.