Dear all, I have deployed Drill on several nodes in the cluster and experienced the query. I have some questions:
1) Can anyone show me some links to read for the Drill execution plan, how to understand it. 2) I execute some group by query on HBase several times, some time very fast, while sometimes very slow, and even get exception, like "Query failed: RemoteRpcException: Failure while running fragment., Command failed while establishing connection. Failure type CONNECTION. [ 2ba2092f-53ed-480a-9f23-f89b6e6a91a0 on test6:31010 ] [ 2ba2092f-53ed-480a-9f23-f89b6e6a91a0 on test6:31010 ] java.lang.RuntimeException: java.sql.SQLException: Failure while executing query. at sqlline.SqlLine$IncrementalRows.hasNext(SqlLine.java:2514) at sqlline.SqlLine$TableOutputFormat.print(SqlLine.java:2148) at sqlline.SqlLine.print(SqlLine.java:1809) at sqlline.SqlLine$Commands.execute(SqlLine.java:3766) at sqlline.SqlLine$Commands.sql(SqlLine.java:3663) at sqlline.SqlLine.dispatch(SqlLine.java:889) at sqlline.SqlLine.begin(SqlLine.java:763) at sqlline.SqlLine.start(SqlLine.java:498) at sqlline.SqlLine.main(SqlLine.java:460)" I am not sure whether Drill uses pre-execute like in Hadoop or auto failure detection. If some of the execution node failed, what will happen? If some node is under high pressure for other task, and what will happen if this node becomes the one who drags the whole execution slow? Thanks! George
