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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/54488/
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Review request for Ambari, Alejandro Fernandez and Nate Cole.
Bugs: AMBARI-19130
https://issues.apache.org/jira/browse/AMBARI-19130
Repository: ambari
Description
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During a downgrade which crosses major stack versions (such as from HDP 2.y to
HDP 2.x), Ambari attempts to set the latest configurations from HDP 2.x as
"current". However, after the downgrade succeeds, the database fails with the
following consistency check:
{code}
ERROR - You have config(s), in cluster c1, that is(are) selected more than once
in clusterconfigmapping table:
ranger-storm-plugin-properties,mapred-env,webhcat-env,hive-exec-log4j,hive-log4j,webhcat-log4j,storm-env,yarn-log4j,hcat-env
{code}
The problem is actually not with {{clusterconfig}} but with the state of the
{{clusterconfigmapping}} table _before_ upgrade. Apparently, it is possible to
have multiple mappings for the same config. We match on the config type and tag
(such as hdfs-site / version1234566789). There should never, EVER be duplicate
mappings for the same config and version tag.
The current downgrade code doesn't "break" after finding its first match:
```
for(ClusterConfigMappingEntity configMappingEntity: configMappingEntities){
String type = configMappingEntity.getType();
String tag = configMappingEntity.getTag();
for (ClusterConfigMappingEntity latest : latestConfigMappingByStack) {
String latestType = latest.getType();
String latestTag = latest.getTag();
// find the latest config of a given mapping entity
if (StringUtils.equals(type, latestType) && StringUtils.equals(tag,
latestTag)) {
LOG.info("{} with version tag {} is selected for stack {}", type, tag,
stackId.toString());
configMappingEntity.setSelected(1);
}
}
}
```
I'm not sure that breaking will work here since we don't know the ordering. We
could order the results and then break on the first match. In any event, it's a
problem. But it's only a problem for the latest version of a config since
that's what we're going to try to make selected.
STR:
# Install a cluster, and instrument the {{clusterconfigmapping}} table to have
multiple mappings for a given type (with only 1 currently selected).
# Upgrade and then downgrade
Diffs
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ambari-server/src/main/java/org/apache/ambari/server/orm/entities/ClusterConfigMappingEntity.java
04c6030
ambari-server/src/main/java/org/apache/ambari/server/state/cluster/ClusterImpl.java
7bf24ce
ambari-server/src/test/java/org/apache/ambari/server/orm/dao/ServiceConfigDAOTest.java
2388c11
ambari-server/src/test/java/org/apache/ambari/server/state/cluster/ClusterTest.java
90a3d02
Diff: https://reviews.apache.org/r/54488/diff/
Testing
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mvn clean test
Thanks,
Jonathan Hurley
