I have faced issues while I want to reload my mosquitto services (MQTT) by /etc/init.d/mosquitto reload.
The MQTT broker doesn't start and I can see my MQTT Port is no longer in netstat.
So far, I only get this following error code that capture from syslog.
segfault at 88 ip 0000000000423f5c sp 00007ffd0f26f530 error 4 in
mosquitto
I am pretty sure the configuration is good to go. However, I faced this issue like yesterday.
I have tried restart the services and yes it worked. But not for reload.
Assuming you are running with mosquitto 1.6.6 then this is a regression that has been fixed in the latest release (1.6.7).
https://mosquitto.org/blog/2019/09/version-1-6-7-released/
Related
I am facing this issue for a couple of days and I am unable to reproduce it outside the Ubuntu Docker container.
Please refer to this simplified diagram of my architecture:
As you can see, I have everything running inside the Docker container.
This is not the typical issue of not being able to connect to inside the container, the whole application runs on the local network of the Docker container.
The Ubuntu Image is the official one with just some packages installed so that everything works (nothing too fancy, just python3 and some c++ tools).
It is running Mosquitto 2.0.15 with the following configuration:
listener 1883
protocol mqtt
allow_anonymous true
log_dest file /home/user/mosquitto.log
So, in summary, I am running an unsecured MQTT broker in the default port 1883. I also added a log file in an attempt to debug what is going on.
On my Python Client, the connection is made in the simplest way possible:
...
self.mqtt_client = mqtt.Client(client_id="Client Id")
self.mqtt_client.connect("localhost", 1883, 6000)
...
self.mqtt_client.loop_start()
...
This Client is able to connect to the broker with no issue at all.
Subscribe and Publish works perfectly too!
On my C++ Client, I try to keep it simple as well:
...
mqtt::async_client MQTTClient("tcp://localhost:1883", "Another Client Id");
MQTTClient.connect()->wait();
...
Yet, this Client fails every attempt to connect to the broker:
terminate called after throwing an instance of 'mqtt::exception'
what(): MQTT error [-1]: TCP/TLS connect failure
Aborted (core dumped)
Although it looks like a SSL/TLS error, this is actually the generic error for when the MQTT broker is not found (If I stop the broker on my local machine I get the same error).
Checking the MQTT broker logs (verbose ON), it does not record anything regarding the attempt to connect from C++ Client:
1672874968: mosquitto version 2.0.15 starting
1672874968: Config loaded from /etc/mosquitto/conf.d/default.conf.
1672874968: Opening ipv4 listen socket on port 1883.
1672874968: mosquitto version 2.0.15 running
(I do get log messages when connecting with Python Client)
On my own Linux machine I am unable to reproduce this issue. Both clients work fine.
I am using the same configuration for the Mosquitto broker and the Clients are exactly the same.
Already tried to play with the IP used to connect to the broker (localhost/127.0.0.1/0.0.0.0) and using different ports, the result is the same.
It is weird that the Python Client can connect with no issue at all.
At this point, I am fairly confident that the issue must be something Docker-specific and how it handles TCP sockets. But I am unable to find anything helpful online.
I can easily check that the port is open:
lsof -i -P -n | grep :1883
mosquitto 56 user 5u IPv4 1633274841 0t0 TCP 127.0.0.1:1883 (LISTEN)
Any ideas what is going on? Or debug tools ideas?
Thanks in advance!
I have tried:
Playing with IP and port of the broker;
Stating the preferable MQTT version (tried with every version);
Run Client with strace and try to find something unusual;
Verify if I am running the exact same Client as my Linux machine;
I finally found out what my issue was.
I had a HTTP proxy configured and Paho C will automatically use this proxy.
It is detecting by checking if "http_proxy" environment variable is set.
My solution was simply unset this variable:
unset http_proxy
Interestingly, the Python MQTT client does not have this behavior.
And for that reason, it worked perfectly!
Today I download neo4j-community-3.2.0 in windows, when i start the server, i meet one problem in browser, i meet this problem in neo4j-community-3.1.2 and i had solved it by Ticking the "Do not use Bolt" option in settings solved the issue. But in neo4j-community-3.2.0 , i can't see "Do not use Bolt" option ,and i don't know how to do.
N/A: WebSocket connection failure. Due to security constraints in your web browser, the reason for the failure is not available to this Neo4j Driver. Please use your browsers development console to determine the root cause of the failure. Common reasons include the database being unavailable, using the wrong connection URL or temporary network problems. If you have enabled encryption, ensure your browser is configured to trust the certificate Neo4j is configured to use. WebSocket readyState is: 3
This happens because the browser is trying (under the hood) to also access the bolt port, which uses an unsigned certificate.
You probably allowed the browser to access the SSL 7474 port through allowing the unsigned certificate as an exception on your browser (and if you didn't, you should in order to make it work).
The url was:
https://[neo4j_host]:7474
Do the same for the bolt certificate, allow it as an exception for url:
https://[neo4j_host]:7687
I ran into the same problem trying to use Neo4j Community Edition on an AWS Ubuntu 16.04 instance. The key thing that solved it was to open port 7687 (the bolt port) in the AWS security group settings.
Found this based on https://stackoverflow.com/a/45234105/1529646
Thus, full answer is:
Make sure to configure Neo4j correctly, ie. uncomment the line dbms.connectors.default_listen_address=0.0.0.0 AND the line dbms.connector.bolt.listen_address=:7687
Open ports 7474 AND 7687 in the AWS security group settings.
In the lower left corner of the browser gear, select do not use bolt.
Open your ${NEO4J_HOME}/conf/neo4j.conf file and edit the bolt settings. It is just about uncommenting this line dbms.connector.bolt.address=0.0.0.0:7687
Change the version of Neo4j
Check your JDK version, use JDK1.8
Adding another option, which worked for me. If your bolt's tls_level is set to REQUIRED, you need to change it to OPTIONAL, if you are not using it with SSL certificate; to get this working.
If you are using Neo4J Community Edition (ver 3.5.1 - in my case) from AWS Marketplace, you need to change the configuration in:
/etc/neo4j/pre-neo4j.sh
Change this line:
echo "dbms_connector_bolt_tls_level" "${dbms_connector_bolt_tls_level:=REQUIRED}"
to
echo "dbms_connector_bolt_tls_level" "${dbms_connector_bolt_tls_level:=OPTIONAL}"
You can find more about Neo4J connector configuration option here. Ideally as per docs, by default bolt.tls_level should have been OPTIONAL only. But I'm not really sure what exactly happened in my case, which got it changed to REQUIRED. Or if it came as is from AWS Marketplace.
Assuming you have valid certs and placed them under the correct certificates directory:
dbms.ssl.policy.bolt.client_auth=NONE
Version 4.0. Took it from this article.
I shared my full ssl config on this other answer.
I had the same error. New to Neo, so take this with a grain of salt, but my solution didn't match these above idea. But thanks as they did lead me to the right "water". So
I went into the conf file, noticed that there was the same port number (previously, the Neo desktop had been constantly telling me it'd needed to update the port numbers...I never checked to verity, but they'd be #, #+1 and #+2. But that didn't work yet that'd happened again and again...but now, after checking the conf file myself, I noticed that the number was the same for all three port requirements for BOLT. Tried that and it didn't work either...but maybe that was important in what did:
In the folder, where the specific database is housed, named "..neo4jdatabases/[GUID Value]" there were two directories titled "/installation-3.4.0" and "...1". I removed the ".0", restarted things and IT WORKED.
So, either there should NOT be two versions under the same database collection OR that's true AND you need the three ports to be the same.
Final add for any Neo4j experts who actually know what they're doing, I have three databases running, two without issue. This occurred AFTER I was messing around trying to see how PowerShell might be useful. Not sure if this is related, but the other databases have worked fine...but, this db is the original playground/sandbox I'd had since the beginning. Not 100% sure, I made the version update before or after, creating the other two databases. HTH.
Using a windows trial version on a Windows 10 machine. Current N4j version is 3.4.1.
Do love what I see so far with Neo BTW!!!
Please mention the correct bolt port under the Connect URL textbox.if you are using the service port the mention the service port in place of bolt port.
Then finally I resolve it by replacing the bolt port with service port inside k8s.
user: neo4j
password: neo4j
I resolve this error by replace the port 7687 with node port 30033 inside Neo4j
then it works fine.
I was facing the same issue with Neo4J version 4 installed on an Ubuntu 18 EC2 instance. Tthe workaround that did the trick for me was to replace the 0.0.0.0 entries in /etc/neo4j/neo4j.conf with the actual private IP of my instance.
Following are the lines where the replace happened:
dbms.default_listen_address=172.X.X.232
dbms.connector.bolt.address=172.X.X.232:7687
Post restart of the DB, the Connect URL when accessing from browser should also use the private IP instead of localhost.
I am trying to setup Neo4j version 3.2.0 in the ubuntu server 14.04.2 LTS
Downloaded the tar and extracted the folder, edited the config file to update the port to 4444, for the time being disabled the bolt connector, listen_address to 0.0.0.0 for the http connector, authentication also disabled just to get started.
bolt connector is updated with the port 7687 even though it is disabled as i was trying earlier with it enabled.
Now when i try to connect to the http://serverip:4444/browser, it says Database access not available and shows me the login screen with host prefilled bolt://serverip:7687
Also I see this error on the console window
WebSocket connection to ws://serverip:7687/
failed: Error in connection establishment:
net::ERR_CONNECTION_TIMED_OUT
Dont understand the issues here, please help me out. I am not sure why is it trying to do a WS to the port assigned to the bolt, when it is disabled at the first place.
Regards
There's a bit of juggling going on for HTTP connector support between the browser and the driver being used, a handoff which isn't complete, and the state of things is the browser is only supporting bolt connections right now.
The javascript bolt driver is being upgraded to handle http connections, I think, so you may need to wait until the next 3.2.x release to use the http connector again.
I think this issue should be tracking it.
Sometimes my ArangoDB is going down with next error:
Error message 'Could not connect to 'tcp://127.0.0.1:8529' 'connect() failed with #10061
I can't understand the reason. It's look like I am turning on my PC and nothing do not work.
Before I fixed this problem with reinstall, but is there any better solution?
OS Windows
ArangoDB 2.8.7
The V8 version used in the pre ArangoDB 3 had occasional troubles in the garbage collection which would make ArangoDB in term go down.
This is fixed with ArangoDB 3.
Please upgrade your installation, and report back whether the problem still persists.
You can use netstat to check whether ArangoDB is listening to its default port 8529:
netstat -a
Active Connections
Proto Lokale Adresse Remoteadresse Status
...
TCP 127.0.0.1:8529 meschenich:0 LISTEN
...
If thats not the case, your client has nothing to connect to.
This could be due to firewall of an antivirus.
In my case it was Avast antivirus that was blocking connecting to that port.
I disabled all the antivirus shields and checked loading arangodb web server
http://127.0.0.1:8529
It connects after few minutes.
Reference : No connection could be made because the target machine actively refused it
I fixed the problem by restarting Windows.
I'm new to Wildfly and I hope you guys can help me with this problem:
I'm following this tutorial on how to Install Wildfly 8 and when I'm trying to execute step 4 I get the following errors:
I've been googling for a while now and I can't find an answer. I've tryed with JDK 7 and 8, no changes, I'm using admin permissions, I've even tried to download Wildfly again and still no changes.
More experienced co-workers have seen this and don't have a clue about what's going on.
Can you help me? Thanks
The tutorial you linked to, has Wildfly configured to use the default port 8080. Most likely, you have another process or service running which is already using port 8080. Try to find out what process it is and stop it, or try configuring Wildfly to use a different port.
try restart the machine or enable IPV6 in the machine, this error will be resolved
Those having the same problem should check who else uses the port 9990 in your Windows system. TCPView is a good tool to find out the guilty of charge. One of possible common causes in this case is NVIDIA Network Service (NvNetworkService.exe).
If that's the case just find it in your Windows services list and stop/disable it. The service itself is responsible for checking for Nvidia drivers updates, so any time you want it back just turn it on manually.
In my case, I inadvertedly added an AJP socket binding while using standalone jboss_cli utility:
[standalone#localhost:9990 /] /subsystem=undertow/server=default-server/ajp-listener=ajp:add(socket-binding=ajp)
This led to an 'already in use' error that doesn't let any app to start and signaled 503 error through an Apache web server.
I deleted the binding:
/subsystem=undertow/server=default-server/ajp-listener=ajp:remove
And then everything worked normally.
I too had the same issue.After analysis it was found that the SSL port(443 in my case) was creating this issue. I just terminated the processes that were running on 443 and restarted the wildfly and everything worked fine after that.
I had faced same issue with wildfly_8.2.1
Port 8080 was also free, so that solution doesn't worked for me.
Try below procedure as it helped to resolve my issue.
add below lines to your server's /etc/sysctl.conf file
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
No restart is required for this solution.