/*
* Request the fault-prober to suspend probes -- no fault actions will
* be taken based on in-flight probes until the prober is unpaused.
*/
bool
gpvars_assign_gp_fts_probe_pause(bool newval, bool doit, GucSource source)
{
if (doit)
{
/*
* We only want to do fancy stuff on the master (where we have a prober).
*/
if (ftsProbeInfo && AmIMaster())
{
/*
* fts_pauseProbes is externally set/cleared;
* fts_cancelProbes is externally set and cleared by FTS
*/
ftsLock();
ftsProbeInfo->fts_pauseProbes = newval;
ftsProbeInfo->fts_discardResults = ftsProbeInfo->fts_discardResults || newval;
ftsUnlock();
/*
* If we're unpausing, we want to force the prober to
* re-read everything. (we want FtsNotifyProber()).
*/
if (!newval)
{
FtsNotifyProber();
}
}
gp_fts_probe_pause = newval;
}
return true;
}
static
void FtsLoop()
{
bool updated_bitmap, processing_fullscan;
MemoryContext probeContext = NULL, oldContext = NULL;
time_t elapsed, probe_start_time;
probeContext = AllocSetContextCreate(TopMemoryContext,
"FtsProbeMemCtxt",
ALLOCSET_DEFAULT_INITSIZE, /* always have some memory */
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
readCdbComponentInfoAndUpdateStatus(probeContext);
for (;;)
{
if (shutdown_requested)
break;
/* no need to live on if postmaster has died */
if (!PostmasterIsAlive(true))
exit(1);
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
}
probe_start_time = time(NULL);
ftsLock();
/* atomically clear cancel flag and check pause flag */
bool pauseProbes = ftsProbeInfo->fts_pauseProbes;
ftsProbeInfo->fts_discardResults = false;
ftsUnlock();
if (pauseProbes)
{
if (gp_log_fts >= GPVARS_VERBOSITY_VERBOSE)
elog(LOG, "skipping probe, we're paused.");
goto prober_sleep;
}
if (cdb_component_dbs != NULL)
{
freeCdbComponentDatabases(cdb_component_dbs);
cdb_component_dbs = NULL;
}
if (ftsProbeInfo->fts_probeScanRequested == ftsProbeInfo->fts_statusVersion)
processing_fullscan = true;
else
processing_fullscan = false;
readCdbComponentInfoAndUpdateStatus(probeContext);
getFailoverStrategy(&failover_strategy);
elog(DEBUG3, "FTS: starting %s scan with %d segments and %d contents",
(processing_fullscan ? "full " : ""),
cdb_component_dbs->total_segment_dbs,
cdb_component_dbs->total_segments);
/*
* We probe in a special context, some of the heap access
* stuff palloc()s internally
*/
oldContext = MemoryContextSwitchTo(probeContext);
/* probe segments */
FtsProbeSegments(cdb_component_dbs, scan_status);
/*
* Now we've completed the scan, update shared-memory. if we
* change anything, we return true.
*/
updated_bitmap = probePublishUpdate(scan_status);
MemoryContextSwitchTo(oldContext);
/* free any pallocs we made inside probeSegments() */
MemoryContextReset(probeContext);
cdb_component_dbs = NULL;
if (!FtsIsActive())
{
if (gp_log_fts >= GPVARS_VERBOSITY_VERBOSE)
elog(LOG, "FTS: skipping probe, FTS is paused or shutting down.");
goto prober_sleep;
}
/*
* If we're not processing a full-scan, but one has been requested; we start over.
*/
if (!processing_fullscan &&
ftsProbeInfo->fts_probeScanRequested == ftsProbeInfo->fts_statusVersion)
continue;
/*
* bump the version (this also serves as an acknowledgement to
* a probe-request).
*/
if (updated_bitmap || processing_fullscan)
{
ftsProbeInfo->fts_statusVersion = ftsProbeInfo->fts_statusVersion + 1;
rescan_requested = false;
}
/* if no full-scan has been requested, we can sleep. */
if (ftsProbeInfo->fts_probeScanRequested >= ftsProbeInfo->fts_statusVersion)
{
/* we need to do a probe immediately */
elog(LOG, "FTS: skipping sleep, requested version: %d, current version: %d.",
(int)ftsProbeInfo->fts_probeScanRequested, (int)ftsProbeInfo->fts_statusVersion);
continue;
}
prober_sleep:
{
/* check if we need to sleep before starting next iteration */
elapsed = time(NULL) - probe_start_time;
if (elapsed < gp_fts_probe_interval && !shutdown_requested)
{
pg_usleep((gp_fts_probe_interval - elapsed) * USECS_PER_SEC);
}
}
} /* end server loop */
return;
}
