OpenSearch SDK for Java Developer Guide

Introduction
Getting Started

Introduction

OpenSearch plugins have allowed the extensibility of various core features. However, the current plugin architecture is tightly coupled with OpenSearch. This creates barriers to innovation and carries the risk of fatally impacting clusters should the plugins fail. In order to ensure that extended functionality may run safely without impacting the system, our goal is to effectively isolate interactions with OpenSearch by modularizing the extension points to which they hook onto.

Getting Started

Presently you need to start up the extension(s) first, and then start OpenSearch.

Clone OpenSearch SDK for Java Repository

Fork OpenSearch SDK for Java and clone locally, e.g. git clone https://github.com/[your username]/opensearch-sdk-java.git.

Run the Sample Extension

Navigate to the directory that OpenSearch SDK for Java has been cloned to.

You can execute the sample Hello World extension using the helloWorld task:

./gradlew helloWorld

Bound addresses will then be logged to the terminal :

[main] INFO  transportservice.TransportService - publish_address {127.0.0.1:3333}, bound_addresses {[::1]:3333}, {127.0.0.1:3333}
[main] INFO  transportservice.TransportService - profile [test]: publish_address {127.0.0.1:5555}, bound_addresses {[::1]:5555}, {127.0.0.1:5555}

Running other extensions

If you are running an extension that uses the SDK, you may simply use ./gradlew run on that extension.

Publish OpenSearch SDK for Java to Maven local

Until we publish this repo to maven central, publishing to maven local is the way for extensions (outside the sample packages) to import the artifacts:

./gradlew publishToMavenLocal

Clone OpenSearch Repository

Fork OpenSearch, clone locally, e.g., git clone https://github.com/[your username]/OpenSearch.git.

Enable Extensions Feature Flag

Add the experimental feature system property to gradle/run.gradle to enable extensions:

testClusters {
  runTask {
    testDistribution = 'archive'
    if (numZones > 1) numberOfZones = numZones
    if (numNodes > 1) numberOfNodes = numNodes
    systemProperty 'opensearch.experimental.feature.extensions.enabled', 'true'
  }
}

Create extensions.yml file

Every extension will require metadata stored in an extensions.yml file in order to be loaded successfully. In order to make the SDK look like an extension within OpenSearch, there must be an entry for the SDK within extensions.yml.

To run OpenSearch from a compiled binary:

Start a separate terminal and navigate to the directory that OpenSearch has been cloned to using cd OpenSearch.
Run ./gradlew assemble to create a local distribution.
Navigate to the project root directory (i.e. cd distribution/archives/linux-tar/build/install/opensearch-3.0.0-SNAPSHOT/). Note: On Mac OS linux-tar should be replaced with darwin-tar.
Check if extensions directory exists in OpenSearch using ls.
If the directory does not exist, create it using mkdir extensions.
Navigate to the extensions folder using cd extensions.
Manually create a file titled extensions.yml within the extensions directory using an IDE or an in-line text editor.
Return to the OpenSearch directory by using cd ...
Start OpenSearch using ./bin/opensearch.

To run OpenSearch from gradle:

Copy the extensions.yml file to the same directory as indicated above.
Run ./gradlew run to start OpenSearch. A log entry will indicate the location it is searching for extensions.yml.

A sample extensions.yml file is shown below. The uniqueId will be used in REST paths. The name must match the extensionName field in the corresponding extension.yml:

extensions:
  - name: hello-world
    uniqueId: opensearch-sdk-java-1
    hostAddress: '127.0.0.1'
    port: '4532'
    version: '1.0'
    opensearchVersion: '3.0.0'
    minimumCompatibleVersion: '3.0.0'

Run OpenSearch

During OpenSearch bootstrap, ExtensionsManager will then discover the extension listenening on a pre-defined port and execute the TCP handshake protocol to establish a data transfer connection. A request will be sent to OpenSearch SDK for Java and upon acknowledgment, the extension will respond with its name which will be logged onto terminal that OpenSearch is running on.

[2022-06-16T21:30:18,857][INFO ][o.o.t.TransportService   ] [runTask-0] publish_address {127.0.0.1:9300}, bound_addresses {[::1]:9300}, {127.0.0.1:9300}
[2022-06-16T21:30:18,978][INFO ][o.o.t.TransportService   ] [runTask-0] Action: internal:transport/handshake
[2022-06-16T21:30:18,989][INFO ][o.o.t.TransportService   ] [runTask-0] TransportService:sendRequest action=internal:discovery/extensions
[2022-06-16T21:30:18,989][INFO ][o.o.t.TransportService   ] [runTask-0] Action: internal:discovery/extensions
[2022-06-16T21:30:19,000][INFO ][o.o.e.ExtensionsManager] [runTask-0] received PluginResponse{examplepluginname}

OpenSearch SDK terminal will also log all requests and responses it receives from OpenSearch :

TCP HandShake Request :

21:30:18.943 [opensearch[extension][transport_worker][T#7]] TRACE org.opensearch.latencytester.transportservice.netty4.OpenSearchLoggingHandler - [id: 0x37b22600, L:/127.0.0.1:4532 - R:/127.0.0.1:47766] READ: 55B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 45 53 00 00 00 31 00 00 00 00 00 00 00 01 08 08 |ES...1..........|
|00000010| 1e ab f3 00 00 00 1a 00 00 00 16 69 6e 74 65 72 |...........inter|
|00000020| 6e 61 6c 3a 74 63 70 2f 68 61 6e 64 73 68 61 6b |nal:tcp/handshak|
|00000030| 65 00 04 a3 8e b7 41                            |e.....A         |
+--------+-------------------------------------------------+----------------+
MESSAGE RECEIVED:E«󀀀internal:tcp/handshake£·A

Extension Name Request / Response :

21:30:18.992 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.latencytester.transportservice.netty4.OpenSearchLoggingHandler - [id: 0xb2be651b, L:/127.0.0.1:4532 - R:/127.0.0.1:47782] READ: 204B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 45 53 00 00 00 c6 00 00 00 00 00 00 00 03 00 08 |ES..............|
|00000010| 2d c7 23 00 00 00 21 00 00 00 1d 69 6e 74 65 72 |-.#...!....inter|
|00000020| 6e 61 6c 3a 64 69 73 63 6f 76 65 72 79 2f 65 78 |nal:discovery/ex|
|00000030| 74 65 6e 73 69 6f 6e 73 00 00 0e 6e 6f 64 65 5f |tensions...node_|
|00000040| 65 78 74 65 6e 73 69 6f 6e 16 51 53 74 39 6f 4b |extension.QSt9oK|
|00000050| 58 46 54 53 57 71 67 58 34 62 6b 56 6a 47 2d 51 |XFTSWqgX4bkVjG-Q|
|00000060| 09 31 32 37 2e 30 2e 30 2e 31 09 31 32 37 2e 30 |.127.0.0.1.127.0|
|00000070| 2e 30 2e 31 04 7f 00 00 01 09 31 32 37 2e 30 2e |.0.1......127.0.|
|00000080| 30 2e 31 00 00 11 b4 00 04 0f 63 6c 75 73 74 65 |0.1.......cluste|
|00000090| 72 5f 6d 61 6e 61 67 65 72 01 6d 00 04 64 61 74 |r_manager.m..dat|
|000000a0| 61 01 64 01 06 69 6e 67 65 73 74 01 69 00 15 72 |a.d..ingest.i..r|
|000000b0| 65 6d 6f 74 65 5f 63 6c 75 73 74 65 72 5f 63 6c |emote_cluster_cl|
|000000c0| 69 65 6e 74 01 72 00 a3 8e b7 41 00             |ient.r....A.    |
+--------+-------------------------------------------------+----------------+
MESSAGE RECEIVED:ES-ǣ!internal:discovery/extensionsnode_extensionQSt9oKXFTSWqgX4bkVjG-Q 127.0.0.1       127.0.0.1  127.0.0.1´cluster_managermdatadingestiremote_cluster_clientr£·A
21:30:18.993 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.transport.TransportLogger - Netty4TcpChannel{localAddress=/127.0.0.1:4532, remoteAddress=/127.0.0.1:47782} [length: 204, request id: 3, type: request, version: 3.0.0, action: internal:discovery/extensions] READ: 204B
21:30:18.993 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.transport.TransportService.tracer - [3][internal:discovery/extensions] received request
21:30:18.996 [opensearch[extension][generic][T#1]] TRACE org.opensearch.tasks.TaskManager - register 2 [transport] [internal:discovery/extensions] []
21:30:18.997 [opensearch[extension][generic][T#1]] TRACE org.opensearch.tasks.TaskManager - unregister task for id: 2
21:30:18.997 [opensearch[extension][generic][T#1]] TRACE org.opensearch.transport.TransportLogger - Netty4TcpChannel{localAddress=/127.0.0.1:4532, remoteAddress=/127.0.0.1:47782} [length: 48, request id: 3, type: response, version: 3.0.0, header size: 2B] WRITE: 48B
21:30:18.998 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.latencytester.transportservice.netty4.OpenSearchLoggingHandler - [id: 0xb2be651b, L:/127.0.0.1:4532 - R:/127.0.0.1:47782] WRITE: 48B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 45 53 00 00 00 2a 00 00 00 00 00 00 00 03 01 08 |ES...*..........|
|00000010| 2d c7 23 00 00 00 02 00 00 16 4e 61 6d 65 64 57 |-.#.......exampl|
|00000020| 72 69 74 65 61 62 6c 65 52 65 67 69 73 74 72 79 |epluginname     |
+--------+-------------------------------------------------+----------------+
21:30:18.999 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.latencytester.transportservice.netty4.OpenSearchLoggingHandler - [id: 0xb2be651b, L:/127.0.0.1:4532 - R:/127.0.0.1:47782] FLUSH
21:30:18.999 [opensearch[extension][transport_worker][T#6]] TRACE org.opensearch.transport.TransportService.tracer - [3][internal:discovery/extensions] sent response

It is important that the OpenSearch SDK for Java is already up and running on a separate process prior to starting OpenSearch, since extension discovery occurs only if the OpenSearch SDK for Java is already listening on a pre-defined port. Once discovery is complete and the data transfer connection between both nodes has been established, OpenSearch and the OpenSearch SDK for Java will now be able to communicate.

Perform a REST Request on the Extension

The following request is configured to be handled by the sample HelloWorldExtension (note the matching uniqueId):

curl -X GET localhost:9200/_extensions/_opensearch-sdk-java-1/hello

Run Tests

Run tests :

./gradlew clean build test

Generate Artifact

In opensearch-sdk-java navigate to build/distributions. Look for tar ball in the form opensearch-sdk-java-1.0.0-SNAPSHOT.tar. If not found follow the below steps to create one:

./gradlew clean && ./gradlew build

Once the tar ball is generated navigate to /src/test/resources/sample and look for extension-settings.yml. Create one if not present Look for tar ball in /build/distributions. To run the artifact i.e., tar ball, run the below command

tar -xvf opensearch-sdk-java-1.0.0-SNAPSHOT.tar

The artifact will include extension settings for the sample extension on the class path under the path /sample/extension-settings.yml. This path is used by the sample HelloWorldExtension.

  extensionName: hello-world
  hostAddress: 127.0.0.1
  hostPort: 4532
  opensearchAddress: 127.0.0.1
  opensearchPort: 9200

Start the sample extension with ./bin/opensearch-sdk-java

Submitting Changes

See CONTRIBUTING.

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DEVELOPER_GUIDE.md

DEVELOPER_GUIDE.md

OpenSearch SDK for Java Developer Guide

Introduction

Getting Started

Clone OpenSearch SDK for Java Repository

Run the Sample Extension

Running other extensions

Publish OpenSearch SDK for Java to Maven local

Clone OpenSearch Repository

Enable Extensions Feature Flag

Create extensions.yml file

Run OpenSearch

Perform a REST Request on the Extension

Run Tests

Generate Artifact

Submitting Changes

Files

DEVELOPER_GUIDE.md

Latest commit

History

DEVELOPER_GUIDE.md

File metadata and controls

OpenSearch SDK for Java Developer Guide

Introduction

Getting Started

Clone OpenSearch SDK for Java Repository

Run the Sample Extension

Running other extensions

Publish OpenSearch SDK for Java to Maven local

Clone OpenSearch Repository

Enable Extensions Feature Flag

Create extensions.yml file

Run OpenSearch

Perform a REST Request on the Extension

Run Tests

Generate Artifact

Submitting Changes