We have a cluster  running cassandra 1.1.4. On this cluster, 

1. We had to move the nodes around a bit  when we were adding new nodes (there was quite a good amount of node movement ) 

2. We had to stop compactions during some of the days to save some disk  space on some of the nodes when they were running very very low on disk spaces. (via nodetool stop COMPACTION)  


As per datastax documentation, a manual compaction forces the admin to start compaction manually and disables the automated compaction (atleast for major compactions but not minor compactions )


Here are the questions I have regarding compaction: 

1. Does a nodetool stop compaction also force the admin to manually run major compaction ( I.e. disable automated major compactions ? ) 

2. Can a node restart reset the automated major compaction if a node gets into a manual mode compaction for whatever reason ? 

3. What is the ideal  number of SSTables for a table in a keyspace ( I mean are there any indicators as to whether my compaction is alright or not ? )  . For example, I have seen SSTables on the disk more than 10 days old wherein there were other SSTables belonging to the same table but much younger than the older SSTables ( The node movement and repair and cleanup happened between the older SSTables and the new SSTables being touched/modified)

4. Does a upgradesstables fix any compaction issues ? 

Regards,
Ananth