JanusGraph 0.6.2对接AWS OpenSearch 7.x遇PermanentBackendException求助

问题场景 #

运行JanusGraph 0.6.2版本，将AWS OpenSearch（Elasticsearch兼容版）7.10作为索引后端，对接6.x版本时一切正常，但连接7.x版本时触发如下异常：

org.janusgraph.diskstorage.PermanentBackendException: method [PUT], host [https://vpc-xxxxxx.us-east-2.es.amazonaws.com:443], URI [/_cluster/settings], status line [HTTP/1.1 401 Unauthorized]
{"Message":"Your request: '/_cluster/settings' payload is not allowed."}

版本信息 #

86   [main] INFO  org.janusgraph.graphdb.server.JanusGraphServer  - JanusGraph Version: 0.6.2
86   [main] INFO  org.janusgraph.graphdb.server.JanusGraphServer  - TinkerPop Version: 3.5.3

详细堆栈 #

3115 [main] INFO  org.janusgraph.diskstorage.Backend  - Configuring index [search]
3387 [main] INFO  com.newforma.janusgraph.es.awsauth.AWSV4AuthHttpClientConfigCallback  - Initialized AWSV4AuthHttpClientConfigCallback for region us-east-2
3782 [main] WARN  org.apache.tinkerpop.gremlin.server.util.DefaultGraphManager  - Graph [graph] configured at [/etc/opt/janusgraph/janusgraph.properties] could not be instantiated and will not be available in Gremlin Server.  GraphFactory message: GraphFactory could not instantiate this Graph implementation [class org.janusgraph.core.JanusGraphFactory]
java.lang.RuntimeException: GraphFactory could not instantiate this Graph implementation [class org.janusgraph.core.JanusGraphFactory]
    at org.apache.tinkerpop.gremlin.structure.util.GraphFactory.open(GraphFactory.java:84)
    at org.apache.tinkerpop.gremlin.structure.util.GraphFactory.open(GraphFactory.java:80)
    ... 14 more
Caused by: java.lang.IllegalArgumentException: Could not instantiate implementation: org.janusgraph.diskstorage.es.ElasticSearchIndex
    at org.janusgraph.util.system.ConfigurationUtil.instantiate(ConfigurationUtil.java:79)
    at org.janusgraph.diskstorage.Backend.getImplementationClass(Backend.java:527)
    at org.janusgraph.diskstorage.Backend.getIndexes(Backend.java:511)
    at org.janusgraph.diskstorage.Backend.<init>(Backend.java:239)
    at org.janusgraph.core.JanusGraphFactory.open(JanusGraphFactory.java:127)
    ... 19 more
Caused by: org.janusgraph.diskstorage.PermanentBackendException: method [PUT], host [https://vpc-xxxxxx.us-east-2.es.amazonaws.com:443], URI [/_cluster/settings], status line [HTTP/1.1 401 Unauthorized]
{"Message":"Your request: '/_cluster/settings' payload is not allowed."}
    at org.janusgraph.diskstorage.es.ElasticSearchIndex.setupMaxOpenScrollContextsIfNeeded(ElasticSearchIndex.java:445)
    at org.janusgraph.diskstorage.es.ElasticSearchIndex.<init>(ElasticSearchIndex.java:388)
    ... 32 more
Caused by: org.elasticsearch.client.ResponseException: method [PUT], host [https://vpc-xxxxxx.us-east-2.es.amazonaws.com:443], URI [/_cluster/settings], status line [HTTP/1.1 401 Unauthorized]
{"Message":"Your request: '/_cluster/settings' payload is not allowed."}
    at org.elasticsearch.client.RestClient.convertResponse(RestClient.java:326)
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:296)
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:270)
    at org.janusgraph.diskstorage.es.rest.RestElasticSearchClient.performRequest(RestElasticSearchClient.java:482)
    at org.janusgraph.diskstorage.es.rest.RestElasticSearchClient.performRequest(RestElasticSearchClient.java:473)
    at org.janusgraph.diskstorage.es.rest.RestElasticSearchClient.updateClusterSettings(RestElasticSearchClient.java:269)
    at org.janusgraph.diskstorage.es.ElasticSearchIndex.setupMaxOpenScrollContextsIfNeeded(ElasticSearchIndex.java:443)

问题原因 #

AWS OpenSearch（包括托管Elasticsearch 7.x及以上版本）限制了通过Elasticsearch API直接修改集群级设置（如action.search.max_open_scroll_contexts），而JanusGraph 0.6.2的Elasticsearch索引后端初始化时，默认会尝试调用PUT /_cluster/settings调整滚动上下文最大值，该操作在AWS托管环境中被拦截，导致401 Unauthorized错误。

解决方案 #

在JanusGraph的配置文件（如janusgraph.properties）中添加以下参数，禁用自动调整滚动上下文的功能：

index.search.es.setup-max-open-scroll-context=false

说明 #

该参数会让JanusGraph跳过初始化阶段修改集群滚动上下文的步骤，避免触发AWS的权限拦截。如果需要调整滚动上下文最大值，需通过AWS控制台或AWS CLI修改OpenSearch集群的参数，而非通过JanusGraph的API操作。

内容的提问来源于stack exchange，提问作者Abhiram