When I search API using the POST/rest/apigateway/search REST API in a clustered environment, I see the following error message in the server log:

019-05-14 12:37:29 CEST [YAI.0300.0014I] [default][node1.kirsa.pl] Error while retrieving Documents for Index gateway_default, Type apis. Cause: org.apache.http.ContentTooLongException: entity content is too long [105063337] for the configured buffer limit [104857600]

This might be due to insufficient response payload size.

Resolution:

Increase the response payload size by setting the pg.gateway.elasticsearch.client.http.response.size property value to a higher value in the config.properties file at the SAGInstallDir\IntegrationServer\instances\default\packages\WmAPIGateway\config\resources\elasticsearch location and restart the API Gateway for the settings to take effect.