ElasticClient Olivere软件包与以前部署的ECS集群保持长期连接

Question

We are currently creating an olivere elastic client in our API like so:

        elasticClient, err = elastic.NewClient(
            elastic.SetURL(elasticSearchUrl),
            elastic.SetSniff(false),
        )

        if err != nil {
            logger.ApplicationError(err)
            time.Sleep(3 * time.Second) 
        } else {
            logger.Information("ElasticSearch: connected")
            return elasticClient
        }
    ...

The single instance client is then used for all in-coming API requests.

However, after a new Elastic cluster is redeployed the connection seems to be still pointing to the old instance since that elasticSearchUrl was only used once for the initial connection.

This creates a problem when are new Elastic Cluster is deployed because a new connection is required.

What would be the best way to achieve a re-connect to the new Elastic Search cluster using this library?

Answer 1

The reason for this is golang is using long-live connections by default. You can disable it by setting the DisableKeepAlives in Transport.

var httpClient = &http.Client{
        Timeout: 60 * time.Second,
        Transport: &http.Transport{
            // Disabel long-live connection
            DisableKeepAlives: true,
            // This is to avoid the time_wait in connections
            MaxIdleConnsPerHost: -1,
        },
    }

elasticClient, err = elastic.NewClient(
            elastic.SetURL(elasticSearchUrl),
            elastic.SetSniff(false),
            elastic.SetHttpClient(httpClient),
        )
   ...