Go Dcp Elasticsearch

Go implementation of the Elasticsearch Connect Couchbase.

Go Dcp Elasticsearch streams documents from Couchbase Database Change Protocol (DCP) and writes to Elasticsearch index in near real-time.

Features

Less resource usage and higher throughput(see Benchmarks).
Custom routing support(see Example).
Update multiple documents for a DCP event(see Example).
Handling different DCP events such as expiration, deletion and mutation(see Example).
Elasticsearch compression request body support.
Managing batch configurations such as maximum batch size, batch bytes, batch ticker durations.
Scale up and down by custom membership algorithms(Couchbase, KubernetesHa, Kubernetes StatefulSet or Static, see examples).
Easily manageable configurations.

Benchmarks

The benchmark was made with the 1,001,006 Couchbase document, because it is possible to more clearly observe the difference in the batch structure between the two packages. Default configurations for Java Elasticsearch Connect Couchbase used for both connectors.

Package	Time to Process Events	Elasticsearch Indexing Rate(/s)	Average CPU Usage(Core)	Average Memory Usage
Go Dcp Elasticsearch(Go 1.20)	50s		0.486	408MB
Java Elasticsearch Connect Couchbase(JDK15)	80s		0.31	1091MB

Example

Struct Config

func mapper(event couchbase.Event) []document.ESActionDocument {
  if event.IsMutated {
    e := document.NewIndexAction(event.Key, event.Value, nil)
    return []document.ESActionDocument{e}
  }
  e := document.NewDeleteAction(event.Key, nil)
  return []document.ESActionDocument{e}
}

func main() {
  connector, err := dcpelasticsearch.NewConnectorBuilder(config.Config{
    Elasticsearch: config.Elasticsearch{
      CollectionIndexMapping: map[string]string{
        "_default": "indexname",
      },
      Urls: []string{"http://localhost:9200"},
    },
    Dcp: dcpConfig.Dcp{
      Username:   "user",
      Password:   "password",
      BucketName: "dcp-test",
      Hosts:      []string{"localhost:8091"},
      Dcp: dcpConfig.ExternalDcp{
        Group: dcpConfig.DCPGroup{
          Name: "groupName",
          Membership: dcpConfig.DCPGroupMembership{
            Type: "static",
          },
        },
      },
      Metadata: dcpConfig.Metadata{
        Config: map[string]string{
          "bucket":     "checkpoint-bucket-name",
          "scope":      "_default",
          "collection": "_default",
        },
        Type: "couchbase",
      },
    },
  }).
    SetMapper(mapper).
    Build()
  if err != nil {
    panic(err)
  }

  defer connector.Close()
  connector.Start()
}

File Config

Default Mapper

Configuration

Dcp Configuration

Check out on go-dcp

Elasticsearch Specific Configuration

Variable	Type	Required	Default	Description
`elasticsearch.collectionIndexMapping`	map[string]string	yes		Defines which Couchbase collection events will be written to which index
`elasticsearch.urls`	[]string	yes		Elasticsearch connection urls
`elasticsearch.username`	string	no		The username of Elasticsearch
`elasticsearch.password`	string	no		The password of Elasticsearch
`elasticsearch.typeName`	string	no		Defines Elasticsearch index type name
`elasticsearch.batchSizeLimit`	int	no	1000	Maximum message count for batch, if exceed flush will be triggered.
`elasticsearch.batchTickerDuration`	time.Duration	no	10s	Batch is being flushed automatically at specific time intervals for long waiting messages in batch.
`elasticsearch.batchByteSizeLimit`	int, string	no	10mb	Maximum size(byte) for batch, if exceed flush will be triggered. `10mb` is default.
`elasticsearch.maxConnsPerHost`	int	no	512	Maximum number of connections per each host which may be established
`elasticsearch.maxIdleConnDuration`	time.Duration	no	10s	Idle keep-alive connections are closed after this duration.
`elasticsearch.compressionEnabled`	boolean	no	false	Compression can be used if message size is large, CPU usage may be affected.
`elasticsearch.concurrentRequest`	int	no	1	Concurrent bulk request count
`elasticsearch.disableDiscoverNodesOnStart`	boolean	no	false	Disable discover nodes when initializing the client.
`elasticsearch.discoverNodesInterval`	time.Duration	no	5m	Discover nodes periodically
`elasticsearch.rejectionLog.index`	string	no	cbes-rejects	Rejection log index name. `cbes-rejects` is default.
`elasticsearch.rejectionLog.includeSource`	boolean	no	false	Includes rejection log source info. `false` is default.

Exposed metrics

Metric Name	Description	Labels	Value Type
elasticsearch_connector_latency_ms	Time to adding to the batch.	N/A	Gauge
elasticsearch_connector_bulk_request_process_latency_ms	Time to process bulk request.	N/A	Gauge
elasticsearch_connector_action_total	Count elasticsearch actions	`action_type`: Type of action (e.g., `delete`, `index`) `result`: Result of the action (e.g., `success`, `error`) `index_name`: The name of the index to which the action is applied	Counter

You can also use all DCP-related metrics explained here. All DCP-related metrics are automatically injected. It means you don't need to do anything.

Grafana Metric Dashboard

Grafana & Prometheus Example

Contributing

Go Dcp Elasticsearch is always open for direct contributions. For more information please check our Contribution Guideline document.

License

Released under the MIT License.

Trendyol / go-dcp-elasticsearch

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