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.
To optimize network and OS performance, configure the following settings in the
/etc/sysctl.conffile of Linux. These settings specify a larger port range, a more effective TCP connection timeout value, and a number of other important parameters at the OS-level.
It is not recommended to use
net.ipv4.tcp_tw_recycle = 1when working with network address translation (NAT), such as if you are deploying products in EC2 or any other environment configured with NAT.
To alter the number of allowed open files for system users, configure the following settings in the
/etc/security/limits.conffile of Linux (be sure to include the leading * character).
Optimal values for these parameters depend on the environment.
To alter the maximum number of processes your user is allowed to run at a given time, configure the following settings in the
/etc/security/limits.conffile of Linux (be sure to include the leading * character). Each carbon server instance you run would require upto 1024 threads (with default thread pool configuration). Therefore, you need to increase the nproc value by 1024 per each carbon server (both hard and soft).
When an XML element has a large number of sub elements and the system tries to process all the sub elements, the system can become unstable due to a memory overhead. This is a security risk.
To avoid this issue, you can define a maximum level of entity substitutions that the XML parser allows in the system. You do this using the
entity expansion limit as follows in the
<APIM_HOME>/bin/wso2server.bat file (for Windows) or the
<APIM_HOME>/bin/wso2server.sh file (for Linux/Solaris). The default entity expansion limit is 64000.
In a clustered environment, the entity expansion limit has no dependency on the number of worker nodes.
WSO2 Carbon platform-level settings
In multitenant mode, the WSO2 Carbon runtime limits the thread execution time. That is, if a thread is stuck or taking a long time to process, Carbon detects such threads, interrupts and stops them. Note that Carbon prints the current stack trace before interrupting the thread. This mechanism is implemented as an Apache Tomcat valve. Therefore, it should be configured in the
<PRODUCT_HOME>/repository/conf/tomcat/catalina-server.xml file as shown below.
classNameis the Java class used for the implementation. Set it to
thresholdgives the minimum duration in seconds after which a thread is considered stuck. The default value is 600 seconds.
Timeout configurations for an API call
The following diagram shows the communication/network paths that occur when an API is called. The timeout configurations for each network call are explained below.
- Get throttle policy
The throttle policy is taken from the registry and is based on your registry configurations. The differences are listed below:
- Local Registry DB in the API Gateway - no network call occurs.
Mount directly to the Registry DB from the
<APIM_HOME>/repository/conf/registry.xmlfile - A DB connection timeout occurs. This can be configured in the
<APIM_HOME>/repository/conf/datasources/master-datasources.xmlfile and depends on the JDBC driver. For example,
Key validation occurs via a Servlet HTTP call and the connection timeout can be configured by changing the following configuration details in the
- Client call API Gateway + API Gateway call Backend
For backend communication, the API Manager uses PassThrough transport. This is configured in the
<APIM_HOME>/repository/conf/passthru-http.propertiesfile. For more information, see Configuring passthru-http.properties in the ESB documentation.
General APIM-level recommendations
Some general APIM-level recommendations are listed below:
|Improvement Area||Performance Recommendations|
|API Gateway nodes|
Increase memory allocated by modifying
|NHTTP transport of API Gateway|
Recommended values for the
# HTTP Sender thread pool parameters
# HTTP Listener thread pool parameters
|PassThrough transport of API Gateway|
Recommended values for the
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.
|Key Manager nodes|
Set the following in the
Set the MySQL maximum connections:
Set the open files limit to 200000 by editing the
Set the following in the
Set the following connection pool elements in the
Note that you set the