Hello, 
suddenly notifications stop working at all. No e-mail or Slack transit notifiers work
 
xxxx@xxxxx:/opt/observium$ sudo ./test_alert.php -a 11569 
Observium 17.10.8927
Test Alert Notification
#####  Software versions  #####
 o OS                   Linux 4.4.0-97-generic [amd64] (Ubuntu 16.04)
 o Apache               2.4.18
 o PHP                  7.0.22-0ubuntu0.16.04.1 (OPcache: ENABLED)
 o Python               2.7.12
 o MySQL                5.7.20-0ubuntu0.16.04.1 (extension: mysqli 5.0.12-dev)
 o SNMP                 NET-SNMP 5.7.3
 o RRDtool              1.5.5
#####  Memory Limit  #####
 o PHP                  Unlimited
#####  MySQL mode  #####
 o MySQL                NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION 
#####  Charset info  #####
 o PHP                  UTF-8
 o MySQL                utf8
#####  Timezones info  #####
 o Date                 Thursday, 26-Oct-17 13:13:45 CEST
 o PHP                  +02:00
 o MySQL                +02:00
 o Queueing Notification  [81049]
 o Queueing Notification  [81050]
With debug flag a lot of these till reach the value Queueing Notification  [81050]
SQL[SELECT * FROM `notifications_queue` WHERE 1]
SQL RUNTIME[0.22802496s]
SQL[SELECT `notification_locked` FROM `notifications_queue` WHERE `notification_id` = '5309']
SQL RUNTIME[0.00024700s]
SQL[SELECT `notification_locked` FROM `notifications_queue` WHERE `notification_id` = '5310']
SQL RUNTIME[0.00008702s]
SQL[SELECT `notification_locked` FROM `notifications_queue` WHERE `notification_id` = '5311']
SQL RUNTIME[0.00007796s]
SQL[SELECT `notification_locked` FROM `notifications_queue` WHERE `notification_id` = '5312']
SQL RUNTIME[0.00007796s]
Any ideas?
Best Regards,
Robert