jmxterm | Interactive command line JMX client | Command Line Interface library

TLDR: running new jmxterm versions as java -jar jmxterm-1.0.2-uber.jar < /dev/tty is a quick, dirty and hacky workaround for having the autocompletion and other stuff work inside the interactive container session.

A quick check shows that jmxterm tries to determine the terminal device used by the process — probably to obtain the terminal capabilities later — by running the tty utility:

Variable names have to be literal, you can't just use an expression as a variable name like you're doing. (Also variable names can't have - in them, but that's a second problem)

bash has associative array variables: you want

To answer your questions:

How can I determine if overlapping sstables is my issue here? I cant see any other reason why the data would not compact out unless it is overlapping related.

If the tombstones weren't generated by using TTL, more of the time the tombstones and the shadowed data could locate into different sstables. When using STCS and there is low volume of write into the cluster, few compaction will be triggered which causes the tombstones stay for extended time. If you have the partition key of a tombstone, run nodetool getsstables --

How can I resolve overlapping sstables, without performing a full compaction? I am afraid this is simply going to reoccur in a few weeks time. I don't want to get stuck having to perform full compactions regularly to keep tombstones at bay.

There is a new option in "nodetool compaction -s" which can do a major compaction and slit the output to 4 sstables with different sizes. This solves the previous problem of the major compaction which creates a single large sstable. If the droppable tombstones ratio is as high as 80-90%, the resulted sstable size will be even smaller as the majority tombstones had been purged.

In the newer version Cassandra (3.10+), there is a new tool, nodetool garbagecollect, to clean up the tombstones. However, there is limitations in this tool. Not all kinds of tombstones could be removed by it.

All being said, for your situation that there are overlapping sstables and low volume of activities/less frequency of compactions, either you have to find out all related sstables and use user defined compaction, or do major compaction with "-s". https://docs.datastax.com/en/dse/5.1/dse-admin/datastax_enterprise/tools/nodetool/toolsCompact.html

What are the reasons for the creation of overlapping sstables? Is this a data design problem, or some other issue?

Fast growing of tombstones usually indicates a data modeling problem: whether the application is inserting null, or periodically deleting data, or using collection and doing update instead of appending. If your data is time series, check if it makes sense to use TTL and TWCS.