several backends optimizations (in file and journal filters):

- don't need to wait if we still had log-entries from last iteration (which got interrupted for servicing)
- rewritten update log/journal position, it is more stable and faster now (fewer DB access and surely up-to-date at end)

fail2ban/server/filter.py

@@ -104,6 +104,10 @@ class Filter(JailThread):
 		## Error counter (protected, so can be used in filter implementations)
 		## if it reached 100 (at once), run-cycle will go idle
 		self._errors = 0
+		## Next time to update log or journal position in database:
+		self._nextUpdateTM = 0
+		## Pending updates (must be executed at next update time or during stop):
+		self._pendDBUpdates = {}
 		## return raw host (host is not dns):
 		self.returnRawHost = False
 		## check each regex (used for test purposes):
@@ -1023,9 +1027,6 @@ class FileFilter(Filter):
 			log = self.__logs.pop(path)
 		except KeyError:
 			return
-		db = self.jail.database
-		if db is not None:
-			db.updateLog(self.jail, log)
 		logSys.info("Removed logfile: %r", path)
 		self._delLogPath(path)
 		return
@@ -1145,9 +1146,15 @@ class FileFilter(Filter):
 					self.processLineAndAdd(line.rstrip('\r\n'))
 		finally:
 			log.close()
-		db = self.jail.database
+		if self.jail.database is not None:
-		if db is not None:
+			self._pendDBUpdates[log] = 1
-			db.updateLog(self.jail, log)
+			if (
+				self.ticks % 100 == 0
+				or MyTime.time() >= self._nextUpdateTM
+				or not self.active
+			):
+				self._updateDBPending()
+				self._nextUpdateTM = MyTime.time() + Utils.DEFAULT_SLEEP_TIME * 5
 		return True
 
 	##
@@ -1247,12 +1254,33 @@ class FileFilter(Filter):
 		ret.append(("File list", path))
 		return ret
 
-	def stop(self):
+	def _updateDBPending(self):
-		"""Stop monitoring of log-file(s)
+		"""Apply pending updates (log position) to database.
 		"""
+		db = self.jail.database
+		while True:
+			try:
+				log, args = self._pendDBUpdates.popitem()
+			except KeyError:
+				break
+			db.updateLog(self.jail, log)
+			
+	def onStop(self):
+		"""Stop monitoring of log-file(s). Invoked after run method.
+		"""
+		# ensure positions of pending logs are up-to-date:
+		if self._pendDBUpdates and self.jail.database:
+			self._updateDBPending()
 		# stop files monitoring:
 		for path in self.__logs.keys():
 			self.delLogPath(path)
+
+	def stop(self):
+		"""Stop filter
+		"""
+		# normally onStop will be called automatically in thread after its run ends, 
+		# but for backwards compatibilities we'll invoke it in caller of stop method.
+		self.onStop()
 		# stop thread:
 		super(Filter, self).stop()
 
@@ -1304,6 +1332,15 @@ class FileContainer:
 		## shows that log is in operation mode (expecting new messages only from here):
 		self.inOperation = tail
 
+	def __hash__(self):
+		return hash(self.__filename)
+	def __eq__(self, other):
+		return (id(self) == id(other) or
+			self.__filename == (other.__filename if isinstance(other, FileContainer) else other)
+		)
+	def __repr__(self):
+		return 'file-log:'+self.__filename
+
 	def getFileName(self):
 		return self.__filename
 

fail2ban/server/filtersystemd.py

@@ -61,7 +61,6 @@ class FilterSystemd(JournalFilter): # pragma: systemd no cover
 		# Initialise systemd-journal connection
 		self.__journal = journal.Reader(**jrnlargs)
 		self.__matches = []
-		self.__nextUpdateTM = 0
 		self.setDatePattern(None)
 		logSys.debug("Created FilterSystemd")
 
@@ -321,6 +320,7 @@ class FilterSystemd(JournalFilter): # pragma: systemd no cover
 				#self.__journal.wait(self.sleeptime) != journal.NOP
 				## 
 				## wait for entries without sleep in intervals, because "sleeping" in journal.wait:
+				if not logentry:
 					Utils.wait_for(lambda: not self.active or \
 						self.__journal.wait(Utils.DEFAULT_SLEEP_INTERVAL) != journal.NOP,
 						self.sleeptime, 0.00001)
@@ -368,15 +368,17 @@ class FilterSystemd(JournalFilter): # pragma: systemd no cover
 				if self.ticks % 10 == 0:
 					self.performSvc()
 				# update position in log (time and iso string):
-				if (line and self.jail.database and (
+				if self.jail.database:
-				    self.ticks % 10 == 0
+					if line:
-				    or MyTime.time() >= self.__nextUpdateTM
+						self._pendDBUpdates['systemd-journal'] = (tm, line[1])
-				    or not self.active
-				  )
-				):
-					self.jail.database.updateJournal(self.jail, 'systemd-journal', tm, line[1])
-					self.__nextUpdateTM = MyTime.time() + Utils.DEFAULT_SLEEP_TIME * 5
 						line = None
+					if self._pendDBUpdates and (
+				    self.ticks % 100 == 0
+				    or MyTime.time() >= self._nextUpdateTM
+				    or not self.active
+				  ):
+						self._updateDBPending()
+						self._nextUpdateTM = MyTime.time() + Utils.DEFAULT_SLEEP_TIME * 5
 			except Exception as e: # pragma: no cover
 				if not self.active: # if not active - error by stop...
 					break
@@ -403,3 +405,22 @@ class FilterSystemd(JournalFilter): # pragma: systemd no cover
 		ret.append(("Journal matches",
 			[" + ".join(" ".join(match) for match in self.__matches)]))
 		return ret
+
+	def _updateDBPending(self):
+		"""Apply pending updates (jornal position) to database.
+		"""
+		db = self.jail.database
+		while True:
+			try:
+				log, args = self._pendDBUpdates.popitem()
+			except KeyError:
+				break
+			db.updateJournal(self.jail, log, *args)
+
+	def onStop(self):
+		"""Stop monitoring of journal. Invoked after run method.
+		"""
+		# ensure positions of pending logs are up-to-date:
+		if self._pendDBUpdates and self.jail.database:
+			self._updateDBPending()
+

fail2ban/server/jailthread.py

@@ -67,6 +67,8 @@ class JailThread(Thread):
 		def run_with_except_hook(*args, **kwargs):
 			try:
 				run(*args, **kwargs)
+				# call on stop callback to do some finalizations:
+				self.onStop()
 			except Exception as e:
 				# avoid very sporadic error "'NoneType' object has no attribute 'exc_info'" (https://bugs.python.org/issue7336)
 				# only extremely fast systems are affected ATM (2.7 / 3.x), if thread ends nothing is available here.
@@ -97,6 +99,12 @@ class JailThread(Thread):
 		self.active = True
 		super(JailThread, self).start()
 
+	@abstractmethod
+	def onStop(self): # pragma: no cover - absract
+		"""Abstract - Called when thread ends (after run).
+		"""
+		pass
+
 	def stop(self):
 		"""Sets `active` property to False, to flag run method to return.
 		"""