This section describes some recommended performance tuning configurations to optimize the API Manager. It assumes that you have set up the API Manager on Unix/Linux, which is recommended for a production deployment. We also recommend a distributed API Manager setup for most production systems. Out of all components of an API Manager distributed setup, the API Gateway is the most critical, because it handles all inbound calls to APIs. Therefore, we recommend you to have at least a 2-node cluster of API Gateways in a distributed setup.
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<Valve className="org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve" threshold="600"/> |
- The
className is the Java class used for the implementation. Set it to org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve. - The
threshold gives the minimum duration in seconds after which a thread is considered stuck. The default value is 600 seconds.
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| Improvement Area | Performance Recommendations |
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| API Gateway nodes | Increase memory allocated by modifying /bin/wso2server. sh with the following setting: - -Xms2048m -Xmx2048m -XX:MaxPermSize=1024m
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| NHTTP transport of API Gateway | Recommended values for <AM_HOME>/repository/conf/nhttp.properties file are given below. Note that the commented out values in this file are the default values that will be applied if you do not change anything. | snd_t_core | Transport sender worker pool's initial thread count | | snd_t_max | Transport sender worker pool's maximum thread count | | snd_io_threads | Sender-side IO workers, which is recommended to be equal to the number of CPU cores. I/O reactors usually employ a small number of dispatch threads (often as few as one) to dispatch I/O event notifications to a greater number (often as many as several thousands) of I/O sessions or connections. Generally, one dispatch thread is maintained per CPU core. | | snd_alive_sec | Sender-side keep-alive seconds | | snd_qlen | Sender queue length, which is infinite by default |
# HTTP Sender thread pool parameters - snd_t_core=200
- snd_t_max=250
- snd_alive_sec=5
- snd_qlen=-1
- snd_io_threads=16
# HTTP Listener thread pool parameters - lst_t_core=200
- lst_t_max=250
- lst_alive_sec=5
- lst_qlen=-1
- lst_io_threads=16
#timeout parameters |
| PassThrough transport of API Gateway | Recommended values for <AM_HOME>/repository/conf/passthru-http.properties file are given below. Note that the commented out values in this file are the default values that will be applied if you do not change anything. worker_thread_keepalive_sec | Defines the keep-alive time for extra threads in the worker pool | | worker_pool_queue_length | Defines the length of the queue that is used to hold runnable tasks to be executed by the worker pool | | io_threads_per_reactor | Defines the number of IO dispatcher threads used per reactor | http.max.connection.per.host.port | Defines the maximum number of connections per host port | | worker_pool_queue_length | Determines the length of the queue used by the PassThrough transport thread pool to store pending jobs. |
worker_thread_keepalive_sec: Default value is 60s. This should be less than the socket timeout. worker_pool_queue_length: Set to -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. The thread pool starts queuing jobs when all the existing threads are busy and the pool has reached the maximum number of threads. So, the recommended queue length is -1. io_threads_per_reactor: Value is based on the number of processor cores in the system. (Runtime.getRuntime().availableProcessors()) http.max.connection.per.host.port : Default value is 32767, which works for most systems but you can tune it based on your operating system (for example, Linux supports 65K connections). - worker_pool_size_core: 400
- worker_pool_size_max: 500
- io_buffer_size: 16384
- http.socket.timeout: 60000
- snd_t_core: 200
- snd_t_max: 250
- snd_io_threads: 16
- lst_t_core: 200
- lst_t_max: 250
- lst_io_threads: 16
Make the number of threads equal to the number of processor cores. |
| Time-out configurations | The API Gateway routes the requests from your client to an appropriate endpoint. The most common reason for your client getting a timeout is when the Gateway's timeout is larger than client's timeout values. You can resolve this by either increasing the timeout on the client's side or by decreasing it on the API Gateway's side. Here are few parameters, in addition to the timeout parameters discussed in the previous sections. | synapse.global_timeout_interval | Defines the maximum time that a callback is waiting in the Gateway for a response from the backend. If no response is received within this time, the Gateway drops the message and clears out the callback. This is a global level parameter that affects all the endpoints configured in Gateway. Global timeout is defined in the <APIM_HOMe>/repository/conf/synapse.properties file. Recommended value is 120000. | | Endpoint-level timeout | You can define timeouts per endpoint for different backend services, along with the action to be taken in case of a timeout. The example below sets the endpoint to 30 seconds and executes the fault handler in case of a timeout. | Code Block |
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| <timeout>
<duration>10000</duration>
<responseAction>fault</responseAction>
</timeout> |
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| Key Manager nodes | Set the following in <APIM_HOME>/repository/conf/axis2/axis2_client.xml file: | Code Block |
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<parameter name="defaultMaxConnPerHost">1000</parameter>
<parameter name="maxTotalConnections">30000</parameter> |
Set the MySQL maximum connections: | Code Block |
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| mysql> show variables like "max_connections";
max_connections was 151
set to global max_connections = 250;
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Set the open files limit to 200000 by editing the /etc/sysctl.conf file: Set the following in <APIM_HOME>/repository/conf/tomcat/catalina-server.xml file. | Code Block |
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maxThreads="750"
minSpareThreads="150"
disableUploadTimeout="false"
enableLookups="false"
connectionUploadTimeout="120000"
maxKeepAliveRequests="600"
acceptCount="600" |
Set the following connection pool elements in <APIM_HOME>/repository/conf/datasources/master-datasources.xml file: | Code Block |
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<maxActive>50</maxActive>
<maxWait>60000</maxWait>
<testOnBorrow>true</testOnBorrow>
<validationQuery>SELECT 1</validationQuery>
<validationInterval>30000</validationInterval> |
Note that you set the <testOnBorrow> element to true and provide a validation query (e.g., in Oracle, SELECT 1 FROM DUAL), which is run to refresh any stale connections in the connection pool. Set a suitable value for the <validationInterval> element, which defaults to 30000 milliseconds. It determines the time period after which the next iteration of the validation query will be run on a particular connection. It avoids excess validations and ensures better performance. |