Up and downgrade failure (5.4.5 <--> 5.7.0)

[#1]

I have upgraded from CDH 5.4.5 to 5.7.0 on a test deployment, to prepare for production upgrade.

After the upgrade to 5.7.0 no CM services could be started (event server, host monitor, etc.). They have timed out after 150 seconds and I was unable to find any error messages apart from this or execute those services manually to get closer to the problem. Then I have decided to downgrade back to 5.4.5, but then it complained that there's no such version as "el7". I though it would solve the problem if remove those lines from parcel, and parcel_components tables from the scm database, but it became worse. Now I'm getting this error, and I'm stuck. It seems that there's still something left behind from 5.7.0, or something cached somewhere. 

Path: http://bdt001:7180/cmf/parcel/topLevelCount

Version: Cloudera Express 5.4.5 (#5 built by jenkins on 20150728-0320 git: 0f47e1327ab87d49c6f504fe3e09e4022fa63ba1)

com.google.common.util.concurrent.UncheckedExecutionException:org.hibernate.PropertyAccessException: Exception occurred inside setter of com.cloudera.cmf.model.DbProcess.resourcesForDb
at LocalCache.java line 2263
in com.google.common.cache.LocalCache$Segment get()


Stack Trace:

LocalCache.java line 2263
in com.google.common.cache.LocalCache$Segment get()
LocalCache.java line 4000
in com.google.common.cache.LocalCache get()
LocalCache.java line 4004
in com.google.common.cache.LocalCache getOrLoad()
LocalCache.java line 4874
in com.google.common.cache.LocalCache$LocalLoadingCache get()
ParcelActiveStatusProviderImpl.java line 68
in com.cloudera.parcel.components.ParcelActiveStatusProviderImpl getParcelActiveStatus()
ClusterParcelStatus.java line 480
in com.cloudera.parcel.ClusterParcelStatus of()
ParcelManagerImpl.java line 606
in com.cloudera.parcel.components.ParcelManagerImpl getParcelStatus()
ParcelManagerImpl.java line 597
in com.cloudera.parcel.components.ParcelManagerImpl getActionCount()
ParcelManagerImpl.java line 70
in com.cloudera.parcel.components.ParcelManagerImpl access$100()
ParcelManagerImpl.java line 123
in com.cloudera.parcel.components.ParcelManagerImpl$1 get()

I would appreciate any idea to solve this. 

I'm using Oracle Java 1.7.0_75-b13, on CentOS 6 servers.

[#2 · Accepted solution]

I have managed to sort things out, as far as the downgrade.

First, I had rebooted every node in the cluster to stop every running process, to start from a clean state.

Second, I have cleared scm database's process and process_active_releases tables.

After that CM was usable at last.

HostMonitor still had an issue with a different LevelDB schema, so I had to clear it's database in /var/lib/cloudera-host-monitor.

After that I just had to restart every service. 

[#3]

If you're in doubt how to do scm database operations:

cd /var/lib/cloudera-scm-server-db/data/
export PGPASSWORD=`head -1 generated_password.txt`
sudo -Eu cloudera-scm psql -p 7432 scm
scm=# delete from process_active_releases;
scm=# delete from processes;