Page Comparison

...

Indexing related configurations are done in the <DAS_HOME>/repository/conf/analytics/analytics-config.xml file. Additionally, information relating to shards is maintained in the <DAS_HOME>/repository/conf/analytics/local-shard-allocation-config.conf file. This file stores the shard number along with its state (that can be INIT or NORMAL). The INIT is the initial state. Usually this state cannot be seen from outside. This is because the INIT state changes to the NORMAL state once the server starts. If the indexing node is running, the state of shards should be NORMAL and not INIT. The NORMAL state denotes that the indexing node has started indexing. Therefore, whenever the data is ready to be indexed, the indexer node indexes the incoming data.To re-index the whole dataset, follow the steps below: Anchorreindexreindex

1. Shut down the WSO2 DAS server.
2. Remove all the index data stored in the <DAS_HOME>/repository/data directory.
3. In the <DAS_HOME>/repository/conf/analytics/local-shard-allocation-config.conf file, change the mode for all the shards from NORMAL to INIT.
4. Restart the WSO2 DAS server.

By default, a single DAS server is configured to have six shards, and one replica for each shard (i.e., a total of twelve shards). Therefore, in a a minimum HA setup, each DAS server contains three shards and replicas of the other three shards. Even if one server is shut down, the second server has replicas of the three shards that were there in the node that was shut down. This allows the high availability to be maintained.

The number of replicas and the number of shards are defined in the the analytics-config.xml. By changing these properties we can change the number of shards and replicas, but once they are defined and the server is started, we cannot change them. Events are are not needed  needed to be published to both nodes. Replication happens through hazelcast messages by sending records to other nodes. 

...

If there are three DAS nodes in the cluster, all twelve shards (i.e., the shards and the replicas) are split among the three nodes. Each node will have four shrds which consists of 2 shards and 2 replicas.

To re-index the whole dataset, follow the steps below:

1. Shut down the WSO2 DAS server.
2. Remove all the index data stored in the <DAS_HOME>/repository/data directory.
3. In the <DAS_HOME>/repository/conf/analytics/local-shard-allocation-config.conf file, change the mode for all the shards from NORMAL to INIT.
4. Restart the WSO2 DAS server.

Debugging Indexing in a cluster

...