With an API txn (and likely other scenarios) cleartablelock will roll
back the txn and lock but leave a stale txn pointer in the BRM. This
causes restart/shutdown to warn that transactions are still open.
This patch makes sure BRM removes the txn from the list.
For some reason version buffer is not turned up for update queries which
means that the version number for dictionary blocks is not changed.
This can lead to dirty cache reads resulting in _CpNoTf_ in the results.
This patch turns on version buffer for updates.
StringStore NULL check includes a check for _CpNuLl_ in the
StringStore. This is a case should never happen but we keep it just in
case.
Unfortunately this check was skipping 4*8 bytes instead of just 4 bytes.
This is definitely bad behaviour but it could cause an out-of-bounds read
based crash.
In the FLOAT/DOUBLE to string conversions a class global string was used
to store the result. Unfortunately it is possible for an instance of
this class to be used by multiple threads of PrimProc simultaneously.
This would cause a race and data corruption or more likely a crash.
This fix passes a string object from the caller to use instead.
Anything that links against joblist will spin up a threadpool upon
startup. This includes the tools setConfig/getConfig. It is possible on
a low core count machine or low CPU speed that the signal to the prune
thread to shutdown is sent before the thread has completed startup when
these quick-running tools are used.
This fix adds a mutex so that spin up and shutdown can't happen at the
same time as well as a stop watch in case we are shutting down when
either the thread is running or we haven't fully started.
When a thread has been idle for 10 minutes and we have too many threads
in the threadpool the thread will be pruned. This is done by the
thread's main function just returning. Unfortunately this does not free
up the memory, the thread either needs to be joined or detatched.
We cannot use detached threads since there are mutexes and conditional
variables between the main thread and the threadpool threads. If the
main thread finishes before the threadpool threads (as would happen in
cpimport) then crashes occur. The parent needs to wait on the child
threads which is the whole point in joining.
So this fix spawns a new thread which every minute will check the list
of threads to be joined due to timeout and join them.
We have had to use an adapted version of boost::thread_group so that we
can join a single thread based off its thread ID.
In addition with have modified PriorityThreadPool to use detached
threads since this does not need to signal the child threads at the end.
This adds options which are user enabled to debug the LRU cache inside
ColumnStore. Specifically cache flushing.
It adds the following:
* PrimProc flush information when SIGUSR2 mode is enabled
* cpimport dictionary flush information when -d2 is used
* WriteEngineServer DML flush information to STDERR
