[DRILL-6251] Queries from system tables hang

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.13.0
• Component/s: Execution - Flow
• Assignee: Unassigned
• Reporter: Vitalii Diravka
• Created: 15/Mar/18 17:24
• Updated: 27/Mar/18 13:37

Description

On CentoOS cluster Drill hangs while querying sys tables after "use dfs;" (embedded or distributed mode):

0: jdbc:drill:> select * from sys.version;
+----------+-------------------------------------------+------------------------------------------------------+----------------------------+--------------------+----------------------------+
| version  |                 commit_id                 |                    commit_message                    |        commit_time         |    build_email     |         build_time         |
+----------+-------------------------------------------+------------------------------------------------------+----------------------------+--------------------+----------------------------+
| 1.13.0   | 796fcf051b3553c4597abbdca5ca247b139734ba  | [maven-release-plugin] prepare release drill-1.13.0  | 13.03.2018 @ 11:39:14 IST  | [e-mail]  | 13.03.2018 @ 13:13:45 IST  |
+----------+-------------------------------------------+------------------------------------------------------+----------------------------+--------------------+----------------------------+
1 row selected (3.784 seconds)
0: jdbc:drill:> use dfs;
+-------+----------------------------------+
|  ok   |             summary              |
+-------+----------------------------------+
| true  | Default schema changed to [dfs]  |
+-------+----------------------------------+
1 row selected (0.328 seconds)
0: jdbc:drill:> select * from sys.version;
Error: Statement canceled (state=,code=0)
0: jdbc:drill:> 

Note: there is no failure on local debian machine with Drill in embedded mode.
dfs pugin configs are default (with "connection": "file:///", other file systems works good).

This failure is connected to DRILL-5089 and Calcite rebase.
Related commits:
https://github.com/apache/drill/commit/450e67094eb6e9a6484d7f86c49b51c77a08d7b2
https://github.com/apache/drill/commit/18a71a38f6bd1fd33d21d1c68fc23c5901b0080a

After analyzing in remote debug I found the following flow:
"dfs" DynamicRootSchema is created, then a new "sys" one is created.
After Calcite validate "sys" SimpleCalciteSchema is created. But in WorkspaceSchemaFactory#create wrong WorkspaceConfig is left and "/" is combined with "sys".