in OTP R16 (and perhaps other OTP releases) there is a failure to fully garbage collect leveled_sst files after thya have initialised. They sppear to maintain a 4MB "hangover" from the initialisation process.
This can be removed by manually calling garbage_collect. So we do this now on all new non-L0 files. A L0 file will be short-lived or switched - short-lived and it doesn't matter, switched and this is already GC'd.
The L0 Pid has used a lot of memory in the construction of the file (something like 50MB). This won't be GC'd immediately. This is fine, as this will normally be short-lived. However if the SST file is switched levels ... then this may mean thta we have multiple SST files with memory not being GC'd.
This is now down on an async message passing loop between the penciller and the new SST file. this way when the penciller it shuts down, and can call close on a L0 file that is awaiting a fetch - rather than be trapped in deadlock.
The deadlock otherwise occurs if a penciller is sent a close immediately after if thas prompted a new level zero.
Make sure there is no change pending regardless of why maybe_roll_memory has been called.
Also, check that the manifest SQN has been incremented before accepting the change.
Conflict here would lead to data loss in the penciller, so extra safety is important.
the Journla snapshot is not a true snapshot, in that the active file in the snapshot can still be taking appends. So when getting a snapshot it is necessary to check if folding over the snapshot that the SQN is <= JournalSQN when the snapshot is taken.
Normally consistency of the snapshot is managed as the operation depends on the penciller, and the penciller *is* a snapshot. Not in this case, as the penciller will return true on a sqn check if the pcl SQN is behind the Journal. So the Journal folder, has been given an additionla check to stop at the JournalSQN.
This is perhaps a fault in the pcl check sqn, which should only return true on an exact match? I'm nervous about changing this though, so we have a less pure fix for now.
These logs duplicate information being received from other logs, so reduced to debug.
The long running test needs to change with the LONG_RUNNING macro
This test (prior tot his commit) works fine. However, something about running it with riak `make test` causes it to fail. The process crashes when the file:delete(F2) is called.
As the test works in isolation on R16, and also because aprocess crashing in the real world in this stage would not be the end of the world (this whole part was added as a way of dealing with some unlikely but possible tidy-up scenarios in eqc tests), losing the test in R16 is tolerable.
So In R16 tests (which includes riak make test), the delete will no longer be called in this test.
The inker cler will now close compacted files before prompting the inker to update the manifest. The inker should reopen those files, so that the file processes are linked to it and not the clerk.
This also stops a stopped clerk leading to orphaned cdb files.
This allows for leveled_iclerk:clerk_stop to be a sync call, so that files will only be closed once the iclerk has stopped. This is designed ot prevent iclerk crashes during shutdowns when files it is depnding on are closed mid shutdown.
Warn at startup if this ratio is high. Not sure how snapshots will perform if there are a lot of ledger cache sin the list. However, it should still work. basic_SUITE/load_count test intended to demonstrate that a large ratio is still functional
A test thta will cause leveled to crash due to a low cache size being set - but protect against this (as well as the general scenario of the cache being full).
There could be a potential case where a L0 file present (post pending) without work backlog being set. In this case we want to roll the level zero to memory, but don't accept the cache update if the L0 cache is already full.
logs should always at least have a log_level defined which is in the ?LOG_LEVELS - so the final case of
`-is_active_level([] , _, _) -> false.`
is unnecessary (even if a bad log level is passed in).
correct Bucket and Key definition to hit expected eunit test cases in leveled_pmem
Will not lead to immediate run time changes in SST or CDB logs. These log settings will only change once the new files are re-written.
To completely change the log level - a restart of the store is necessary with new startup options.
