Vihang Karajgaonkar created IMPALA-11028:
--------------------------------------------
Summary: Table loading could fail if metastore cleans up old events
Key: IMPALA-11028
URL: https://issues.apache.org/jira/browse/IMPALA-11028
Project: IMPALA
Issue Type: Bug
Reporter: Vihang Karajgaonkar
Assignee: Vihang Karajgaonkar
After IMPALA-10502, Catalogd tracks the table's create event id. When the table
is loaded for the first time, it updates the create event id of the table. But
if the table is loaded for the first time after a long delay (after 24 hrs) it
is possible the metastore cleans up old notification logs entries which are
required by catalogd during the table load.
See this snippet from TableLoader.java
{noformat}
if (eventId != -1 && catalog_.isEventProcessingActive()) {
// If the eventId is not -1 it means this table was likely created by
Impala.
// However, since the load operation of the table can happen much
later, it is
// possible that the table was recreated outside Impala and hence the
eventId
// which is stored in the loaded table needs to be updated to the
latest.
// we are only interested in fetching the events if we have a valid
eventId
// for a table. For tables where eventId is unknown are not created by
// this catalogd and hence the self-event detection logic does not
apply.
events = MetastoreEventsProcessor.getNextMetastoreEvents(catalog_,
eventId,
notificationEvent -> CreateTableEvent.CREATE_TABLE_EVENT_TYPE
.equals(notificationEvent.getEventType())
&& notificationEvent.getDbName().equalsIgnoreCase(db.getName())
&& notificationEvent.getTableName().equalsIgnoreCase(tblName));
}
{noformat}
{{getNextMetastoreEvents}} method can throw the following exception if the
metastore has cleaned up older entries (by default 24 hrs). This is controlled
by configuration {{hive.metastore.event.db.listener.timetolive}} on the
metastore side.
I could reproduce the problem setting the following metastore configs.
{noformat}
hive.metastore.event.db.listener.clean.interval=10s
hive.metastore.event.db.listener.timetolive=120s
{noformat}
Now run the following Impala script
{noformat}
create table t1 (c1 int);
create table t2 (c1 int);
select sleep(240000);
create table t3 (c1 int);
select * from t1;
{noformat}
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
