NullPointerException on readDocument()

[mkozioro]

SDK Version: 1.16.0

We see following errors in logs:

java.lang.NullPointerException: null
        at com.microsoft.azure.documentdb.internal.SessionContainer.compareAndSetToken(SessionContainer.java:194)
        at com.microsoft.azure.documentdb.internal.SessionContainer.setSessionToken(SessionContainer.java:167)
        at com.microsoft.azure.documentdb.internal.SessionContainer.setSessionToken(SessionContainer.java:156)
        at com.microsoft.azure.documentdb.internal.SessionTokenHelper.captureSessionToken(SessionTokenHelper.java:138)
        at com.microsoft.azure.documentdb.DocumentClient.captureSessionToken(DocumentClient.java:3155)
        at com.microsoft.azure.documentdb.DocumentClient.doRead(DocumentClient.java:3054)
        at com.microsoft.azure.documentdb.DocumentClient.readDocument(DocumentClient.java:1041)
        at com.tomtom.lns.batch.dao.CosmosDBDao.getDocumentByBatchId(CosmosDBDao.java:358)

java.lang.NullPointerException: null
        at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
        at com.microsoft.azure.documentdb.internal.SessionContainer.getPartitionKeyRangeIdToTokenMap(SessionContainer.java:72)
        at com.microsoft.azure.documentdb.internal.SessionContainer.resolveGlobalSessionToken(SessionContainer.java:88)
        at com.microsoft.azure.documentdb.internal.SessionContainer.resolveGlobalSessionToken(SessionContainer.java:84)
        at com.microsoft.azure.documentdb.DocumentClient.applySessionToken(DocumentClient.java:3143)
        at com.microsoft.azure.documentdb.DocumentClient.doRead(DocumentClient.java:3051)
        at com.microsoft.azure.documentdb.DocumentClient.readDocument(DocumentClient.java:1041)
        at com.tomtom.lns.batch.dao.CosmosDBDao.getDocumentByBatchId(CosmosDBDao.java:358)

Our retrieve method:

private Document getDocumentByBatchId(final DocumentClient client, final BatchId batchId) {
    try {
      final RequestOptions requestOptions = new RequestOptions();
      requestOptions.setPartitionKey(new PartitionKey(batchId.getUuid().toString()));
      requestOptions.setConsistencyLevel(ConsistencyLevel.Strong);
      return client.readDocument(getBatchDocumentLink(batchId), requestOptions).getResource();
    } catch (DocumentClientException e) {
      if (e.getStatusCode() == HttpStatus.NOT_FOUND.value()) {
        throw new BatchNotFoundException(batchId);
      }
      throw new IllegalStateException("Cannot fetch Batch document: " + batchId, e);
    }
  }

And for clarity getBatchDocumentLink() method:

private static final String BATCH_DOCUMENT_LINK_TEMPLATE = "/dbs/BatchDB/colls/batches/docs/%s"
...
  private String getBatchDocumentLink(final BatchId batchId) {
    return String.format(BATCH_DOCUMENT_LINK_TEMPLATE, batchId.getUuid().toString());
  }

Our DocumentClient is created by:

  private DocumentClient createDocumentClient(final String url, final String masterKey,
      final ImmutableList<String> preferredLocations) {
    final ConnectionPolicy connectionPolicy = new ConnectionPolicy();
    connectionPolicy.setEnableEndpointDiscovery(true);
    connectionPolicy.setConnectionMode(ConnectionMode.DirectHttps);
    connectionPolicy.setMaxPoolSize(CONNECTION_POOL_SIZE);
    connectionPolicy.setPreferredLocations(preferredLocations);
    return new DocumentClient(url, masterKey, connectionPolicy, ConsistencyLevel.Session);
  }

[srinathnarayanan]

Hi @mkozioro how often are you seeing this? Which version of the SDK are you using?

[mkozioro]

Hi @srinathnarayanan
We are using SDK Version: 1.16.0. We're not getting that often. Less than 20 times, while running our app stress test. It just looks strange and we don't have source codes to check it.

We stopped to see that error after removing requestOptions.setConsistencyLevel(ConsistencyLevel.Strong);
line. I'm not sure if we shouldn't set that consistency level or there is a bug in SDKs.