[SENTRY-1007] Sentry column-level performance for wide tables

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.5.1
• Fix Version/s: 1.7.0
• Assignee: Dapeng Sun
• Reporter: Anne Yu
• Created: 12/Jan/16 19:16
• Updated: 30/Jan/16 07:35
• Resolved: 30/Jan/16 07:24

Description

It appears a query is taking a long time on a wide table due many Sentry column-level auth checks.

here are some investigation results:

1) create a table with 4000 columns, grant select on [table|db] to test user, however

select * from table

still validates column level privilege on each column. So this select command issues 4000 queries to validate column level permissions. It takes 40 seconds on my test cluster (2x large) to return results, for a moment, query seems to freeze:

...
2016-01-11 11:54:14,816 INFO DataNucleus.Query: Reading in results for query "SELECT FROM org.apache.sentry.provider.db.service.model.MSentryPrivilege WHERE roles.contains(role) && (role.roleName == "test_role") && serverName == "server1" && ((dbName == "test_db") || (dbName == "__NULL__")) && (URI == "__NULL__") && ((tableName == "test_tb") || (tableName == "__NULL__")) && (URI == "__NULL__") && ((columnName == "test997") || (columnName == "__NULL__")) && (URI == "__NULL__") VARIABLES org.apache.sentry.provider.db.service.model.MSentryRole role" since the connection used is closing
2016-01-11 11:54:14,822 INFO DataNucleus.Query: Reading in results for query "SELECT FROM org.apache.sentry.provider.db.service.model.MSentryPrivilege WHERE roles.contains(role) && (role.roleName == "test_role") && serverName == "server1" && ((dbName == "test_db") || (dbName == "__NULL__")) && (URI == "__NULL__") && ((tableName == "test_tb") || (tableName == "__NULL__")) && (URI == "__NULL__") && ((columnName == "test998") || (columnName == "__NULL__")) && (URI == "__NULL__") VARIABLES org.apache.sentry.provider.db.service.model.MSentryRole role" since the connection used is closing
2016-01-11 11:54:14,828 INFO DataNucleus.Query: Reading in results for query "SELECT FROM org.apache.sentry.provider.db.service.model.MSentryPrivilege WHERE roles.contains(role) && (role.roleName == "test_role") && serverName == "server1" && ((dbName == "test_db") || (dbName == "__NULL__")) && (URI == "__NULL__") && ((tableName == "test_tb") || (tableName == "__NULL__")) && (URI == "__NULL__") && ((columnName == "test999") || (columnName == "__NULL__")) && (URI == "__NULL__") VARIABLES org.apache.sentry.provider.db.service.model.MSentryRole role" since the connection used is closing

Here is the debug log from sentry service:

org.apache.sentry.binding.hive.authz.HiveAuthzBinding.authorize(HiveAuthzBinding.java:304)] requiredInputPrivileges = {Table=[SELECT], Column=[SELECT], URI=[ALL]}

2) the same issue for

show columns in table

3) for

show count(*) in table

, it requires table level privilege, so this issue doesn't exist.

4) I found out there are more commands have the same issues are:

SHOW COLUMNS FROM test_tb1;
create table test_tb2 as select * from test_tb1
show partitions in test_tb1
select * from test_tb1

Even for

select col1,col2,col3 from test_tb1

will issue 3 queries for each column, instead of one query for all columns in one table;

Issue Links

• is related to: SENTRY-1040 Add config to optionally disable caching introduced in SENTRY-1007
• is related to: SENTRY-1041 Investigate options for cache Sentry policy for Hive requests