[[timeout-best-practices]] === Timeout best practices Starting in 9.0.0, this client is configured to not time out any HTTP request by default. {es} will always eventually respond to any request, even if it takes several minutes. Reissuing a request that it has not responded to yet can cause performance side effects. See the {ref}/modules-network.html#_http_client_configuration[official {es} recommendations for HTTP clients] for more information. Prior to 9.0, this client was configured by default to operate like many HTTP client libraries do, by using a relatively short (30 second) timeout on all requests sent to {es}, raising a `TimeoutError` when that time period elapsed without receiving a response. If your circumstances require you to set timeouts on Elasticsearch requests, setting the `requestTimeout` value to a millisecond value will cause this client to operate as it did prior to 9.0.