Configuring connection timeout on Message Processors

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This document explains how to configure the connection timeout for the Apigee Edge Message Processors.

The connection timeout represents time for which the Message Processor waits to establish connection with the target server. The default value of the connection timeout property on the Message Processor is 3 seconds. This timeout period is applicable to the backend servers configured in the target endpoint configuration and in the ServiceCallout policy of your API proxy.

The connection timeout for Message Processors can be increased or decreased from the default value of 3 seconds based on your needs. It can be configured in the following ways:

  • In the API proxy
    • In the target endpoint
    • In the ServiceCallout policy
  • On the Message Processor

The following properties control the connection timeout on the Message Processors:

Property name Location Description
connect.timeout.millis API proxy:
  • Target endpoint
  • ServiceCallout policy

This is the maximum time which the Message Processor waits to connect with the target server.

By default, this property takes the value set for the HTTPClient.connect.timeout.millis property on Message Processor, where the default value is 3 seconds.

If this property is modified with a new timeout value for the target server associated with an API proxy, then the connect time only for that target server is affected.

HTTPClient.connect.timeout.millis Message Processor

This is the maximum time which the Message Processor waits to connect to the target server.

This property is used for all the API proxies running on this Message Processor.

The default value of this property is 3 seconds.

You can either modify this property as explained in Configuring connection timeout on Message Processors below, or you can overwrite this value by setting the connect.timeout.millis property at the API proxy level.

Before you begin

Before you use the steps in this document, be sure you understand the following topics:

Configuring connection timeout in API proxy

The connection timeout can be configured in the API proxy in the following places:

  • Target endpoint
  • ServiceCallout policy

Configuring connection timeout in target endpoint of API proxy

This section explains how to configure connection timeout in the target endpoint of your API proxy. The connection timeout can be configured through the property connect.timeout.millis, which represents the connection timeout value in milliseconds.

  1. In the Edge UI, select the specific API proxy in which you would like to configure the new connection timeout value.
  2. Select the specific target endpoint that you want to modify.
  3. Add the property connect.timeout.millis with an appropriate value under the <HTTPTargetConnection> element in the TargetEndpoint configuration.

    For example, to change the connection timeout to 5 seconds, add the following block of code:

    <Properties>
      <Property name="connect.timeout.millis">5000</Property>
    </Properties>
    

    Since the connect.timeout.millis property is in milliseconds, the value for 5 seconds is 5000.

    The following examples show how to configure the connection timeout in the target endpoint configuration of your API proxy:

    Example target endpoint configuration using URL for backend server

    <TargetEndpoint name="default">
      <HTTPTargetConnection>
        <URL>https://mocktarget.apigee.net/json</URL>
        <Properties>
          <Property name="connect.timeout.millis">5000</Property>
        </Properties>
      </HTTPTargetConnection>
    </TargetEndpoint>
    

    Example target endpoint configuration using target server

    <TargetEndpoint name="default">
      <HTTPTargetConnection>
        <LoadBalancer>
          <Server name="target1" />
          <Server name="target2" />
        </LoadBalancer>
        <Properties>
          <Property name="connect.timeout.millis">5000</Property>
        </Properties>
        <Path>/test</Path>
      </HTTPTargetConnection>
    </TargetEndpoint>
    
  4. Save the changes made to your API proxy.

Configuring connection timeout in ServiceCallout policy of API proxy

This section explains how to configure the connection timeout in the ServiceCallout policy of your API proxy. The connection timeout can be configured through the connect.timeout.millis property, which represents the connect time value in milliseconds.

To configure the connection timeout in the ServiceCallout policy using the connect.timeout.millis property:

  1. In the Edge UI, select the specific API proxy in which you would like to configure the new connection timeout value for the ServiceCallout policy.
  2. Select the specific ServiceCallout policy that you want to modify.
  3. Add the property connect.timeout.millis with an appropriate value under the <HTTPTargetConnection> element in the TargetEndpoint configuration.

    For example to change the connection timeout to 5 seconds, add the following block of code:

    <Properties>
      <Property name="connect.timeout.millis">5000</Property>
    </Properties>
    

    Since the connect.timeout.millis property is in milliseconds, the value for 5 seconds is 5000.

    The following examples show how to configure the connection timeout in the ServiceCallout policy of your API proxy:

    Example ServiceCallout policy configuration using URL for backend server

    <ServiceCallout name="Service-Callout-1">
      <DisplayName>Service Callout-1</DisplayName>
      <HTTPTargetConnection>
        <Properties>
          <Property name="connect.timeout.millis">5000</Property>
        </Properties>
        <URL>https://mocktarget.apigee.net/json</URL>
      </HTTPTargetConnection>
    </ServiceCallout>
    

    Example ServiceCallout policy configuration using target server

    <ServiceCallout enabled="true" name="Service-Callout-1">
      <DisplayName>Service Callout-1</DisplayName>
      <Response>calloutResponse</Response>
      <HTTPTargetConnection>
        <LoadBalancer>
          <Server name="target1" />
          <Server name="target2" />
        </LoadBalancer>
        <Properties>
          <Property name="connect.timeout.millis">5000</Property>
        </Properties>
      <Path>/test</Path>
      </HTTPTargetConnection>
    </ServiceCallout>
    
  4. Save the changes made to your API proxy.

Configuring connection timeout on Message Processors

This section explains how to configure the connection timeout on the Message Processors. The connection timeout can be configured through the property conf_http_HTTPClient.connect.timeout.millis, which represents the connection timeout value in milliseconds on the Message Processor component, using the token according to the syntax described in How to configure Edge.

To configure the connection timeout on the Message Processors, do the following:

  1. On the Message Processor machine, open the following file in an editor. If it does not already exist, then create it.
    /opt/apigee/customer/application/message-processor.properties
    

    For example, to open the file using vi, enter the following:

    vi /opt/apigee/customer/application/message-processor.properties
    
  2. Add a line in the following format to the properties file, substituting a value for TIME_IN_MILLISECONDS:
    conf_http_HTTPClient.connect.timeout.millis=TIME_IN_MILLISECONDS
    

    For example, to change the connection timeout on the Message Processor to 5 seconds, add the following line:

    conf_http_HTTPClient.connect.timeout.millis=5000
    
  3. Save your changes.
  4. Ensure the properties file is owned by the apigee user as shown below:
    chown apigee:apigee /opt/apigee/customer/application/message-processor.properties
    
  5. Restart the Message Processor as shown below:
    /opt/apigee/apigee-service/bin/apigee-service edge-message-processor restart
    
  6. If you have more than one Message Processor, repeat the above steps on all the Message Processors.

Verifying connection timeout on Message Processors

This section explains how to verify that the connection timeout has been successfully modified on the Message Processors.

Even though you use the token conf_http_HTTPClient.connect.timeout.millis to set the connection timeout on the Message Processor, you need to verify if the actual property HTTPClient.connect.timeout.millis has been set with the new value.

  1. On the Message Processor machine, search for the property HTTPTransport.connect.timeout.millis in the /opt/apigee/edge-message-processor/conf directory and check to see if it has been set with the new value as shown below:
    grep -ri "HTTPClient.connect.timeout.millis" /opt/apigee/edge-message-processor/conf
    
  2. If the new connection timeout value is successfully set on the Message Processor, then the above command shows the new value in the http.properties file.

    The sample result from the above command after you have configured connection timeout to 5 seconds is as follows:

    /opt/apigee/edge-message-processor/conf/http.properties:HTTPClient.connect.timeout.millis=5000
    

    In the example output above, notice that the property HTTPClient.connect.timeout.millis has been set with the new value 5000 in http.properties. This indicates that the connection timeout is successfully configured to 5 seconds on the Message Processor.

  3. If you still see the old value for the property HTTPClient.connect.timeout.millis, then verify that you have followed all the steps outlined in Configuring connection timeout on Message Processors correctly. If you have missed any step, repeat all the steps again correctly.
  4. If you are still not able to modify the connection timeout, then contact Google Cloud Apigee Support.