Merge pull request #63 from Calvario/patch-1

Patch 1
ottorei · Oct 29, 2024 · a383f78 · a383f78
2 parents 2c78729 + ec14999
commit a383f78
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diff --git a/LibreNMS/queuemanager.py b/LibreNMS/queuemanager.py
@@ -537,6 +537,56 @@ def __init__(self, config, lock_manager):
 
     def do_work(self, device_id, group):
         if self.lock(device_id, timeout=self.config.poller.frequency):
+            # We need to check if the device was polled recently to prevent a race condition
+            # We have 3 cases:
+            # 1. The last_polled_timetaken is greater than the poller frequency, we can poll the device
+            # The last_polled_timetaken is less than the poller frequency cap to maximum 15 seconds
+            #   2. If the last_polled is greater than the cap, we can poll the device
+            #   3. If the last_polled is less than the cap, we skip polling the device
+            dbPollerQueueManager = LibreNMS.DB(self.config)
+            try:
+                select_last_polled = dbPollerQueueManager.query(
+                    "SELECT last_polled >= NOW() - INTERVAL LEAST(%s - last_polled_timetaken, 15) SECOND AS is_poll_recent, "
+                    "last_polled, last_polled_timetaken FROM devices WHERE device_id=%s",
+                    (self.config.poller.frequency, device_id),
+                )
+                value_last_polled = select_last_polled.fetchone()
+                logger.info(
+                    "Last polled timestamp for device {}: {} (is_poll_recent: {}, last_polled_timetaken: {})".format(
+                        device_id,
+                        value_last_polled[1],
+                        value_last_polled[0],
+                        value_last_polled[2],
+                    )
+                )
+                # If is_poll_recent is 1, then the device was polled recently
+                if value_last_polled[0] == 1:
+                    logger.warning(
+                        "Skipping polling for device {} as it was polled recently".format(
+                            device_id
+                        )
+                    )
+                    self.unlock(device_id)
+                    return
+            except pymysql.err.Error as e:
+                logger.critical(
+                    "A DB Exception occurred while checking the last_polled of device {}: {}".format(
+                        device_id, str(e)
+                    )
+                )
+                self.unlock(device_id)
+                return
+            except Exception as e:
+                logger.error(
+                    "An exception occurred while checking the last_polled of device {}: {}".format(
+                        device_id, str(e)
+                    )
+                )
+                self.unlock(device_id)
+                return
+            finally:
+                dbPollerQueueManager.close()
+
             logger.info("Polling device {}".format(device_id))
 
             args = (

diff --git a/LibreNMS/service.py b/LibreNMS/service.py
@@ -611,14 +611,14 @@ def fetch_immediate_device_list(self):
             result = self._db.query(
                 """SELECT `device_id`,
                   `poller_group`,
-                  COALESCE(`last_polled` <= DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_polled_timetaken`, 0) SECOND), 1) AS `poll`,
-                  IF(status=0, 0, IF (%s < `last_discovered_timetaken` * 1.25, 0, COALESCE(`last_discovered` <= DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_discovered_timetaken`, 0) SECOND), 1))) AS `discover`
+                  COALESCE(`last_polled` < DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_polled_timetaken`, 0) SECOND), 1) AS `poll`,
+                  IF(status=0, 0, IF (%s < `last_discovered_timetaken` * 1.25, 0, COALESCE(`last_discovered` < DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_discovered_timetaken`, 0) SECOND), 1))) AS `discover`
                 FROM `devices`
                 WHERE `disabled` = 0 AND (
                     `last_polled` IS NULL OR
                     `last_discovered` IS NULL OR
-                    `last_polled` <= DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_polled_timetaken`, 0) SECOND) OR
-                    `last_discovered` <= DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_discovered_timetaken`, 0) SECOND)
+                    `last_polled` < DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_polled_timetaken`, 0) SECOND) OR
+                    `last_discovered` < DATE_ADD(DATE_ADD(NOW(), INTERVAL -%s SECOND), INTERVAL COALESCE(`last_discovered_timetaken`, 0) SECOND)
                 )
                 ORDER BY `last_polled_timetaken` DESC""",
                 (