What is the problem?
Octoprint failed to connect to my printer after successfully connecting many times before. It sat overnight disconnected and this happened on the next connect the next morning.
What did you already try to solve it?
After getting this error, I tried clicking on the Connect button in the GUI. Nothing happened so I clicked it again and, again, nothing happened. So, I tried restarting Octoprint from the pulldown menu and got this:
Using the SSH interface, I executed an 'sudo systemctl restart octoprint' command. That completed successfully and, after refreshing the GUI, I was able to connect to the printer successfully.
Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)
2020-05-08 13:49:06,822 - octoprint.server.heartbeat - INFO - Server heartbeat <3
2020-05-08 13:49:18,585 - octoprint.plugins.tracking - INFO - Sent tracking event ping, payload: {'octoprint_uptime': 184514}
2020-05-08 13:50:41,007 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 13:50:41,010 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 13:52:41,017 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 13:52:41,019 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 13:54:41,027 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 13:54:41,029 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 13:56:41,036 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 13:56:41,037 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 13:58:41,044 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 13:58:41,051 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 14:00:41,061 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 14:00:41,066 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 14:02:41,076 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 14:02:41,079 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 14:04:06,831 - octoprint.server.heartbeat - INFO - Server heartbeat <3
2020-05-08 14:04:18,548 - octoprint.plugins.tracking - INFO - Sent tracking event ping, payload: {'octoprint_uptime': 185414}
2020-05-08 14:04:41,086 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 14:04:41,087 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 14:06:41,096 - octoprint.plugins.mqtt - ERROR - Connection to mqtt broker refused, not authorised
2020-05-08 14:06:41,100 - octoprint.plugins.mqtt - ERROR - Disconnected from mqtt broker for unknown reasons (network error?), rc = 5
2020-05-08 14:07:45,276 - octoprint.util.comm - INFO - Changing monitoring state from "Offline" to "Opening serial port"
2020-05-08 14:07:45,306 - octoprint.util.comm - INFO - Changing monitoring state from "Opening serial port" to "Connecting"
2020-05-08 14:07:45,339 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-05-08 14:07:45,364 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-05-08 14:07:45,367 - octoprint.util.comm - ERROR - Something crashed inside the serial connection loop, please report this in OctoPrint's bug tracker:
Traceback (most recent call last):
File "/home/pi/oprint/local/lib/python2.7/site-packages/octoprint/util/comm.py", line 2175, in _monitor
self._onConnected()
File "/home/pi/oprint/local/lib/python2.7/site-packages/octoprint/util/comm.py", line 2482, in _onConnected
self._temperature_timer.start()
File "/usr/lib/python2.7/threading.py", line 736, in start
_start_new_thread(self.__bootstrap, ())
error: can't start new thread
2020-05-08 14:07:45,383 - octoprint.util.comm - INFO - Changing monitoring state from "Connecting" to "Offline (Error: See octoprint.log for details)"
2020-05-08 14:07:45,613 - octoprint.plugins.influxdb - ERROR - Disconnected from InfluxDB. Attempting to reconnect.
Traceback (most recent call last):
File "/home/pi/oprint/local/lib/python2.7/site-packages/octoprint_influxdb/__init__.py", line 155, in influx_emit
self.influx_db.write_points([point])
File "/home/pi/oprint/local/lib/python2.7/site-packages/influxdb/client.py", line 599, in write_points
consistency=consistency)
File "/home/pi/oprint/local/lib/python2.7/site-packages/influxdb/client.py", line 676, in _write_points
protocol=protocol
File "/home/pi/oprint/local/lib/python2.7/site-packages/influxdb/client.py", line 410, in write
headers=headers
File "/home/pi/oprint/local/lib/python2.7/site-packages/influxdb/client.py", line 369, in request
raise InfluxDBClientError(err_msg, response.status_code)
InfluxDBClientError: 400: {"error":"partial write: max-series-per-database limit exceeded: (1000000) dropped=1"}
2020-05-08 14:07:45,628 - octoprint.plugins.influxdb - INFO - connecting: database='octoprint', host='10.248.0.30', ssl=False, use_udp=False
2020-05-08 14:07:45,738 - octoprint.plugins.influxdb - INFO - Using existing database `octoprint`
2020-05-08 14:07:45,748 - octoprint.plugins.stats - INFO - Printer Stats - on_event
2020-05-08 14:07:45,980 - octoprint.plugins.stats - INFO - Printer Stats - on_event
2020-05-08 14:07:46,297 - octoprint.plugins.tracking - INFO - Sent tracking event commerror_crash, payload: {'commerror_text': u'See octoprint.log for details'}
The MQTT errors are due to the fact that I had forgotten to configure Octoprint with username and password in the MQTT plugin. I configured those values and the errors went away.
After seeing that the problem seemed to be related to thread creation, I checked the memory state with 'top' and here is the result:
top - 14:19:16 up 3 days, 58 min, 1 user, load average: 0.26, 0.33, 0.43
Tasks: 110 total, 1 running, 109 sleeping, 0 stopped, 0 zombie
%Cpu(s): 3.4 us, 4.4 sy, 0.0 ni, 92.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 864.6 total, 256.9 free, 161.7 used, 445.9 buff/cache
MiB Swap: 100.0 total, 100.0 free, 0.0 used. 634.2 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
21113 pi 20 0 2073136 111700 19620 S 31.7 12.6 627:57.63 octoprint
9699 pi 20 0 10216 3016 2592 R 1.4 0.3 0:00.24 top
10 root 20 0 0 0 0 I 0.5 0.0 2:02.89 rcu_sched
420 root 20 0 26516 4296 4088 S 0.5 0.5 9:24.08 mjpg_streamer
6984 root 20 0 0 0 0 I 0.5 0.0 0:01.78 kworker/0:1-events_power_efficient
9249 pi 20 0 12544 4584 3704 S 0.5 0.5 0:00.14 sshd
1 root 20 0 33808 8100 6428 S 0.0 0.9 0:12.19 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.36 kthreadd
3 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_gp
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_par_gp
8 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 mm_percpu_wq
9 root 20 0 0 0 0 S 0.0 0.0 0:45.98 ksoftirqd/0
11 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_bh
12 root rt 0 0 0 0 S 0.0 0.0 0:00.14 migration/0
13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/0
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/1
15 root rt 0 0 0 0 S 0.0 0.0 0:00.18 migration/1
16 root 20 0 0 0 0 S 0.0 0.0 0:00.53 ksoftirqd/1
19 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/2
20 root rt 0 0 0 0 S 0.0 0.0 0:00.21 migration/2
21 root 20 0 0 0 0 S 0.0 0.0 0:00.39 ksoftirqd/2
24 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/3
25 root rt 0 0 0 0 S 0.0 0.0 0:00.19 migration/3
26 root 20 0 0 0 0 S 0.0 0.0 0:07.78 ksoftirqd/3
29 root 20 0 0 0 0 S 0.0 0.0 0:00.01 kdevtmpfs
30 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 netns
34 root 20 0 0 0 0 S 0.0 0.0 0:00.42 khungtaskd
35 root 20 0 0 0 0 S 0.0 0.0 0:00.00 oom_reaper
36 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 writeback
37 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kcompactd0
38 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 crypto
39 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kblockd
40 root rt 0 0 0 0 S 0.0 0.0 0:00.00 watchdogd
41 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rpciod
42 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/u9:0-hci0
43 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 xprtiod
46 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kswapd0
47 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 nfsiod
58 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kthrotld
60 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 iscsi_eh
61 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 dwc_otg
62 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 DWC Notificatio
63 root 1 -19 0 0 0 S 0.0 0.0 0:00.07 vchiq-slot/0
64 root 1 -19 0 0 0 S 0.0 0.0 0:00.00 vchiq-recy/0
65 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 vchiq-sync/0
66 root 20 0 0 0 0 S 0.0 0.0 0:00.00 vchiq-keep/0
67 root 10 -10 0 0 0 S 0.0 0.0 0:00.00 SMIO
69 root -51 0 0 0 0 S 0.0 0.0 0:00.01 irq/86-mmc1
Given that there did not appear to be a memory issue, I did not dig into the proc and sys filesystems for more clues.
The serial log looked like this:
2020-05-08 14:07:45,258 - Connecting to: /dev/ttyACM0
2020-05-08 14:07:45,276 - Changing monitoring state from "Offline" to "Opening serial port"
2020-05-08 14:07:45,297 - Connected to: Serial<id=0x6545f550, open=True>(port='/dev/ttyACM0', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=10.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
2020-05-08 14:07:45,304 - Changing monitoring state from "Opening serial port" to "Connecting"
2020-05-08 14:07:45,340 - Send: N0 M110 N0*125
2020-05-08 14:07:45,350 - Recv: ok
2020-05-08 14:07:45,366 - Send: N0 M110 N0*125
2020-05-08 14:07:45,375 - See octoprint.log for details
2020-05-08 14:07:45,383 - Changing monitoring state from "Connecting" to "Offline (Error: See octoprint.log for details)"
2020-05-08 14:07:45,437 - Connection closed, closing down monitor
2020-05-08 14:17:53,356 - Connecting to: /dev/ttyACM0
2020-05-08 14:17:53,367 - Changing monitoring state from "Offline" to "Opening serial port"
2020-05-08 14:17:53,372 - Connected to: Serial<id=0x6733ead0, open=True>(port='/dev/ttyACM0', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=10.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
2020-05-08 14:17:53,379 - Changing monitoring state from "Opening serial port" to "Connecting"
2020-05-08 14:18:23,432 - No answer from the printer within the connection timeout, trying another hello
2020-05-08 14:18:33,453 - There was a timeout while trying to connect to the printer
2020-05-08 14:18:33,472 - Changing monitoring state from "Connecting" to "Offline"
2020-05-08 14:18:33,484 - Connection closed, closing down monitor
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
Octoprint: 1.4.0
Octopi: octopi-buster-lite-0.17.0
Printer: DIY cartesian using an SKR v1.3 (LPC1768-based) control board running Marlin 2.0.5.3.
Browser: Chrome Version 81.0.4044.129 (Official Build) (64-bit)
OS: Microsoft Windows 10 Pro version 10.0.18362 Build 18362