# OpenSearch output

The OpenSearch output can be used to send records to [OpenSearch](https://opensearch.org/), [Open Distro for OpenSearch](https://opendistro.github.io/for-elasticsearch/) and [Amazon OpenSearch Service](https://aws.amazon.com/opensearch-service/).

## EF\_OUTPUT\_OPENSEARCH\_ENABLE

Specifies whether the OpenSearch output is enabled.

* Valid Values
  * `true`, `false`
* Default
  * `false`

## EF\_OUTPUT\_OPENSEARCH\_ECS\_ENABLE

Specifies whether the data will be sent using Elastic Common Schema (ECS).

* Valid Values
  * `true`, `false`
* Default
  * `false`

## EF\_OUTPUT\_OPENSEARCH\_BATCH\_DEADLINE

The maximum time, in milliseconds, to wait for a batch of records to fill before being sent to the OpenSearch bulk API.

* Default
  * `2000`

## EF\_OUTPUT\_OPENSEARCH\_BATCH\_MAX\_BYTES

The maximum size, in bytes, for a batch of records being sent to the OpenSearch bulk API.

* Default
  * `8388608`

## EF\_OUTPUT\_OPENSEARCH\_TIMESTAMP\_SOURCE

Determines the timestamp source to be used to set the `@timestamp` field. Usually `end` would be the best setting. However, in the case of poorly behaving or misconfigured devices, `collect` may be the better option.

:::info Beginning with ElastiFlow `6.3.0` the OpenSearch output's default value for this setting was changed to `collect`. This will allow the collector to handle a wider variety of situations without additional configuration. If you wish to continue to use the old default setting of `end`, you should ensure that it is specifically set in your configuration. :::

* Valid Values
  * `start` - Use the timestamp from `flow.start.timestamp`. The flow start time indicated in the flow.
  * `end` - Use the timestamp from `flow.end.timestamp`. The flow end time (or last reported time).
  * `export` - Use the timestamp from `flow.export.timestamp`. The time from the flow record header.
  * `collect` - Use the timestamp from `flow.collect.timestamp`. The time that the collector processed the flow record.
* Default
  * `collect`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_PERIOD

:::caution Beginning with ElastiFlow `6.4.0` the OpenSearch output's default value for this setting will be changed to `rollover`. This will enable the use of Index State Management (ISM) to manage retention of ElastiFlow indices. If you wish to continue to use the old default setting of `daily`, you should ensure that it is specifically set in your configuration. :::

* Valid Values
  * `daily` - New indices will be created each day. The format of the time period suffix will be `-yyyy.MM.dd`.
  * `weekly` - New indices will be created each week. The format of the time period suffix will be `-yyyy.'w'ww`.
  * `monthly` - New indices will be created each month. The format of the time period suffix will be `-yyyy.MM`.
  * `rollover` - Index State Management will be used to handle the creation and deletion of indices.
* Default
  * `daily`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_SUFFIX

It can sometimes be useful to have separate indices for different environments, locations or other organizational unit. This settings allow you to specify a suffix that will be added to the index for such purposes.

* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_ENABLE

Specifies whether the output should attempt to add the required index template to OpenSearch.

* Valid Values
  * `true`, `false`
* Default
  * `true`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_OVERWRITE

If the output is configured to add the index template to OpenSearch (`EF_OUTPUT_OPENSEARCH_INDEX_TEMPLATE_ENABLE` is `true`), this setting determines whether the index template should be overwritten if it already exists.

* Valid Values
  * `true`, `false`
* Default
  * `false`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_SHARDS

The number of shards with which the index should be created. As a general rule, additional shards increases ingest performance, assuming there are sufficient data nodes across which the shards can be distributed.

* Recommended
  * Equal to the number of OpenSearch data nodes to which data will be indexed.
* Default
  * `3`

:::note This setting configures the index template sent to OpenSearch. It does NOT change any existing indices. :::

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_REPLICAS

The number of replicas that should be created for each shard. If using a multi-node cluster and data redundancy is desired, this value must be at least `1`.

In general, additional replicas will increase query performance, assuming there are sufficient data nodes across which the replicas can be distributed.

* Recommended
  * `1` if indexing data to a multi-node cluster.
  * `0` for a single-node.
* Default
  * `1`

:::note This setting configures the index template sent to OpenSearch. It does NOT change any existing indices. :::

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_REFRESH\_INTERVAL

Specifies the period for the refresh interval. The refresh interval is the time window in which newly ingested documents are added to a segment, prior to the segment being added to the index. Only after the refresh interval has ended and the segment has been added to the index do the documents become searchable.

* Recommended
  * `5s` - If the data needs to become available for queries more quickly. However shorter refresh intervals will negatively impact ingest performance.
  * `30s` - (or longer) If maximizing ingest performance is the highest priority. Longer refresh intervals negatively impact the real-time accessibility of new records.
  * `10s` or `15s` - This is a reasonable compromise between ingest performance and data accessibility for most network traffic analytics use-cases.
* Default
  * `10s`

:::note This setting configures the index template sent to OpenSearch. It does NOT change any existing indices. :::

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_CODEC

The setting determines the level of compression used for stored values.

* Valid Values
  * `default` - Stored values are compressed using LZ4.
  * `best_compression` - Stored values are compressed using DEFLATE. This reduces disk capacity requirements with the trade-off of slightly higher CPU utilization.
* Default
  * `best_compression`

:::note This setting configures the index template sent to OpenSearch. It does NOT change any existing indices. :::

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_ISM\_POLICY

If data is being stored to an Open Distro for OpenSearch cluster, this setting specifies the Index State Management (ISM) Policy ID that should be applied to the indices.

:::note The ISM Policy itself MUST be configured separately in OpenSearch. If `EF_OUTPUT_OPENSEARCH_INDEX_PERIOD` is set to `rollover` a default ISM policy will be added automatically with the name defined in this setting. :::

* Default
  * `elastiflow`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_PIPELINE\_DEFAULT

If it is desired to process the incoming with an OpenSearch Ingest Pipeline prior to it being indexed, this setting specifies the name of the default pipeline.

* Default
  * `_none`

## EF\_OUTPUT\_OPENSEARCH\_INDEX\_TEMPLATE\_PIPELINE\_FINAL

If it is desired to process the incoming with an OpenSearch Ingest Pipeline prior to it being indexed, this setting specifies the name of the final pipeline.

* Default
  * `_none`

## EF\_OUTPUT\_OPENSEARCH\_ADDRESSES

This setting specifies the OpenSearch servers to which the output should connect. It is a comma-separated list of OpenSearch nodes, including port number.

:::danger Do **NOT** include `http://` or `https://` in the provided value. TLS communications is enabled/disabled using `EF_OUTPUT_OPENSEARCH_TLS_ENABLE`. :::

* Default
  * `127.0.0.1:9200`

## EF\_OUTPUT\_OPENSEARCH\_USERNAME

The username to use when connecting to OpenSearch.

* Default
  * `admin`

## EF\_OUTPUT\_OPENSEARCH\_PASSWORD

The password to use when connecting to OpenSearch.

* Default
  * `admin`

## EF\_OUTPUT\_OPENSEARCH\_AWS\_ACCESS\_KEY

The AWS Access key to use when connecting to OpenSearch via Auth Sig V4

## EF\_OUTPUT\_OPENSEARCH\_AWS\_SECRET\_KEY

The AWS Secret key to use when connecting to OpenSearch via Auth Sig V4

## EF\_OUTPUT\_OPENSEARCH\_AWS\_REGION

The AWS Region to use when connecting to OpenSearch via Auth Sig V4

## EF\_OUTPUT\_OPENSEARCH\_CLIENT\_CA\_CERT\_FILEPATH

The path to the Certificate Authority (CA) certificate to use for client PKI authentication.

* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_CLIENT\_CERT\_FILEPATH

The path to the client certificate to use for client PKI authentication.

* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_CLIENT\_KEY\_FILEPATH

The path to the client key to use for client PKI authentication.

* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_TLS\_ENABLE

This setting is used to enable/disable TLS connections to OpenSearch.

* Valid Values
  * `true`, `false`
* Default
  * `false`

## EF\_OUTPUT\_OPENSEARCH\_TLS\_SKIP\_VERIFICATION

This setting is used to enable/disable TLS verification of the OpenSearch server to which the output is attempting to connect.

* Valid Values
  * `true`, `false`
* Default
  * `false`

## EF\_OUTPUT\_OPENSEARCH\_TLS\_CA\_CERT\_FILEPATH

The path to the Certificate Authority (CA) certificate to use for verification of the OpenSearch server to which the output is attempting to connect.

* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_RETRY\_ENABLE

Specifies whether to retry connecting to OpenSearch after a connection has failed.

* Valid Values
  * `true`, `false`
* Default
  * `true`

## EF\_OUTPUT\_OPENSEARCH\_RETRY\_ON\_TIMEOUT\_ENABLE

Specifies whether to retry bulk indexing requests which have timed-out.

* Valid Values
  * `true`, `false`
* Default
  * `true`

## EF\_OUTPUT\_OPENSEARCH\_MAX\_RETRIES

Specifies the number of times to retry bulk indexing requests which have timed-out.

* Default
  * `3`

## EF\_OUTPUT\_OPENSEARCH\_RETRY\_BACKOFF

If set, this value specifies the quantity of milliseconds that the output should "backoff" prior to retrying a failed bulk request.

* Default
  * `1000`

## EF\_OUTPUT\_OPENSEARCH\_DROP\_FIELDS

This setting allows for a comma-separated list of fields that are to be removed from all records.

:::note Fields are dropped after any output specific fields have been added and after any schema conversion. This means that you should use the field names as you see them in the user interface. :::

* Valid Values
  * any field names related to the enabled schema, comma-separated
* Example
  * `flow.export.sysuptime,flow.export.version.ver,flow.start.sysuptime,flow.end.sysuptime,flow.seq_num`
* Default
  * `''`

## EF\_OUTPUT\_OPENSEARCH\_ALLOWED\_RECORD\_TYPES

This setting allows for a comma-separated list of record types that the output will send will emit. This is particularly useful when used with multiple namespaced outputs, e.g. sending flow records to one datastore and telemetry to another.

* Valid Values
  * `as_path_hop`, `flow_option`, `flow` , `telemetry`
* Default
  * `'as_path_hop,flow_option,flow,telemetry'`