I have cloned a Spark project from git which I surely know works and operates correctly. When I run the program, the Jetty server ignites and looks like listening with no problem. Here is the console for that:
[Thread-0] INFO org.eclipse.jetty.util.log - Logging initialized #402ms
[Thread-0] INFO spark.webserver.JettySparkServer - == Spark has ignited ...
[Thread-0] INFO spark.webserver.JettySparkServer - >> Listening on 0.0.0.0:4567
[Thread-0] INFO org.eclipse.jetty.server.Server - jetty-9.3.2.v20150730
[Thread-0] INFO org.eclipse.jetty.server.ServerConnector - Started ServerConnector#36a9b54a{HTTP/1.1,[http/1.1]}{0.0.0.0:4567}
[Thread-0] INFO org.eclipse.jetty.server.Server - Started #600ms
But when I send a request from any browser on my computer, it returns always empty response. I have configuration for the database and all and tried the same configuration with the same data on another computer and it works right away. I have look for the TCP connection status with TCPview and I saw that connection directly goes into time_wait state. Since it does not occur on the other computer I have tested, I'm guessing that the problem does not come from the program or database, but something causes this especially on my computer. Any opinion is appreciated. Thanks.
Make sure you're accessing your webservice like this http://localhost:4567/yourRouteName, note that Spark runs on a not so common port (I wold say), that can be locked by firewall policies or other security software, but you can change the port number like doing it this port(8080); before setting any route.
If nothing works, we would need more information, could you please share the source code of any route you're unable to access ?
Related
I have a setup where I use Flask-MQTT to connect my python Flask API to a Mosquitto broker. Whenever I run the Flask API with the development server all is well. But whenever I spin it up for production (using wsgi+nginx), the connection with Mosquitto is made, but everytime i try to publish something i get the following error:
Socket error on client <unknown>, disconnecting.
My app.ini has the processes configured to 1 (processes = 1)
My mosquitto.config has the allow_anonymous flag set to trye (allow_anonymous true)
I can't really seem to figure out what I'm doing wrong here...
Update:
So what i think is happening is that the Flask-uwsgi application is trying to connect to mosquitto more than once. There is a master process that connects with Mosquitto on initialize. Then there is a second process that is being used whenever input is given on the Flask app. I'm not sure, but I think Mosquitto only wants one connection at the time, therefor erroring on the second. So now i either need to:
A) Configure Mosquitto in a way that it accepts multiple connection from the same device
B) Configure Flask in a way that wil only use one single process (configuring processes = 1 is not enough, it will still spawn two processes)
99% of the time, a "Socket error on client <unknown>" is an authentication error. I don't know Flask, so I don't know where to point you at, but something in your code is either trying to pass a username/password that is not defined to Mosquitto, or its trying a TLS connection with an cert that Mosquitto doesn't like.
Alright, it turns I could've read that the whole multiple processes wouldn't work from the start at the official Flask-MQTT documentation. It sais right there in think letters:
Flask-MQTT is currently not suitable for the use with multiple worker
instances.
So I looked at my uwsgi app.ini file again closely and actually the answer is quite simple. I turned out i had a like in there master = true.. after I removed that it works like a charm.
I am working with IBM MQ. I managed to get a basic Handshake / Put Message(s) / Get Message(s) / Disconnect .net solution going on, a couple of days ago, but it only works on a local level, and I now need to update the solution so it works remotely as well.
After reading and experimenting for a while, I decided to follow IBM Knowledge Center's Point to Point scenario step by step. However, I can't start the Sender Channel as instructed by the guide's last step; the Sender Channel's status ping-pongs between Binding and Retrying, and the logs come up with the following error codes; AMQ9002, AMQ9202 and AMQ9999, meaning, as far as I can tell, there is some kind of trouble finding and/or connecting with the host, as explained by the error logs.
I have looked through a lot of questions regarding these errors in particular, but while I have followed most of the proposed solutions (I made sure the Receiver's listener is running, I tried turning off Firewalls, I tried with different ports, I have performed tests Telnet, I have stopped/restarted/resolved the Sender channel a few times, and I have tried setting this up from both, the command line and MQ Explorer), I have yet to get a successful communication going on between two different PCs.
I am aware the error could be either temporary, or the result of problems within the Network itself, but I have been trying to establish a successful connection for almost three days now, and before I pass this unto my bosses I would like to make sure I have exhausted every other possibility.
How can I complete IBM's Point To Point set up guide, or is there anything that could point me towards a different / better approach to get two PCs talking with each other via IBM MQ v9?
Although hastily translated from Japanese, you can find the detailed error logs below.
2017/09/19 17:34:09 - Process (234212.1) User (MUSR_MQADMIN) Program
(runmqchl.exe)
Host (DESKTOP - UP 4 D 363) Installation (Installation 1)
VRMF (9.0.3.0) QMgr (QM 1)
Time (2017-09-19T08: 34: 09.201 Z)
AMQ9002: Channel 'TO.QM2' is starting.
Description: Channel 'TO.QM2' is starting.
ACTION: None.
2017/09/19 17:34:30 - Process (234212.1) User (MUSR_MQADMIN) Program
(runmqchl.exe)
Host (DESKTOP - UP4D363) Installation (Installation 1)
VRMF (9.0.3.0) QMgr (QM 1)
Time (2017-09-19T08: 34: 30.824Z)
AMQ 9202: The remote host 'DESKTOP-1AV4LM3 (The correct ip address) (1415)' can not be used.Please try again later.
Description: Using TCP / IP to host 'DESKTOP-1AV4LM3 (The correct ip
address) of channel TO.QM2 (1415) 'trying to allocate a conversation,
but it did not succeed. However, It is temporary and there is also the
possibility that TCP / IP conversation can be allocated normally
later.
If the remote host can not be determined, '????' is displayed. .
ACTION: Please try the connection later. If the failure persists,
record the error value Please contact the stem administrator. The
return code from TCP / IP is 10060 (X'274C ').The cause of this
failure may be that the host can not reach the destination host.
Alternatively, There is a possibility that the host 'DESKTOP-1AV4LM3
(The correct ip address) (1415)' listener isn't running. If that is
the case, start the listener and try again.
2017/09/19 17:34:30 - Process (234212.1) User (MUSR_MQADMIN) Program (runmqchl.exe)
Host (DESKTOP - UP 4 D 363) Installation (Installation 1)
VRMF (9.0.3.0) QMgr (QM 1)
Time (2017-09-19T08: 34: 30.825Z)
AMQ9999: Channel 'TO.QM2' for host 'DESKTOP-1AV4LM3 (1415)' terminated abnormally
Description: The host 'DESKTOP-1AV4LM3 (1415)' cannot be determined.
ACTION: Check the error log for the preceding error message for
this channel program Please determine the cause of failure....
".
The 'interesting' bit of the error messages above is that the sender is attempting to start a channel to port 1415 on the destination and is getting a 10060 return code (WSAETIMEDOUT). This is different from an immediate rejection because the other end doesnt have a socket open, for example.
You will also note its timing out after about 21 seconds if your times are to be believed. The only time I've seen this kind of things is DNS resolution - There was an APAR for example showing that reverse DNS can cause delays in channel startup, and this could be for a successful or unsuccessful startup
http://www-01.ibm.com/support/docview.wss?uid=swg1IC96408
A new attribute was added to MQ to disable reverse DNS lookups if its the cause - See https://www.ibm.com/support/knowledgecenter/en/SSFKSJ_8.0.0/com.ibm.mq.pro.doc/q113120_.htm#q113120___chlauth
If this is the case, on the receiving end (or both!) try runmqsc , 'ALTER QMGR REVDNS(DISABLED)'. You might have to restart the qmgr for it to be effective (I'm not sure, sorry)
I'd also echo the comment added to your question by JoshMc, to check the receiving end logs for messages (both global errors but more likely the qmgr specific AMQERR01.LOG files) when this occurs - I have a feeling that the timeout is only part of your problem.
I created a web application, here is the architecture :
Tomcat7 deploy on Amazon EC2
Granite DS
nginx to redirect HTTPS throught the tomct7 port 8181
Flex application that uses RemoteObject on a secure Channel.
Occasionaly, maybye when a request takes to long time, the execution of a RemoteObject in Flex triggers this error :
faultCode:Channel.Call.Failed faultString:'error' faultDetail:'NetConnection.Call.Failed: HTTP: Status 504'
But in the most time, the response of the Remote object is correct.
Could you tell me if Nginx could block something? Or if BlazeDs has a tomeout?Any clues?
Thank you very much
We've had this issue for a long time...problem is we haven't been able to find a repeatable way to force it to disconnect.
Here the most comprehensive list of things to try that i've been able to find:
http://www.bopit.in.th/2009/10/14/flex-channel-connect-failed-error-netconnection-call-failed-http-status-200/
We've tried a couple of those solutions and it seems like we're getting less client disconnects.
There also may be a problem with AVG's linkscanner hijacking the request as it leaves the browser, and then losing it somewhere. We had one machine in our shop that would disconnect when using IE, and since uninstalling AVG, it's never happened on that machine again.
another thing you could check is the socket timeout:
NetConnection.Call.Failed happening sporadically in Flex3/Tomcat/BlazeDS/Spring
and here is a thread on adobe forum about the issue:
http://forums.adobe.com/thread/552133
We currently experience a problem with a self-written server application running on Windows (occurs on different versions). The server listens at a TCP port, accepts connections, exchanges some data and then closes the connections again. There are about 100 clients that connect from time to time.
Sometimes the server stops to work: Log files show that connections are still accepted, but that at the first read attempt a socket error (10054 - Connection reset by peer) occurs. I don't think it is a client issue because it suddenly stops working for all clients.
Now we found out, that the same problem occurs with our old server software, that is even written in another programming language. So it doesn't seem to be an error in our program - I think it has to be some kind of OS / firewall issue? Of course, firewalls have been deactivated, which didn't solve the issue yet.
Any ideas where to look into? Wireshark logs will follow soon..
Excerpt from the log (Timestamp, Thread Id, message)
11:37:56.137 T#3960 Connection from 10.21.13.3
11:37:56.138 T#3960 Client Exception: Socket Error # 10054
Connection reset by peer.
11:37:56.138 T#3960 ClientDisconnected
11:38:00.294 T#4144 Connection from 10.21.13.3
You can see that the exception occurs almost at the same time as the connection is accepted, in this case the client reconnects after a few seconds.
A "stateful" firewall or NAT keeps track of connections, and ought to send RSTs for connectiosn it doesn't know about. If the firewall loses track of connections for some reason, then you'll probably see random connections being reset.
Our router at work does this — it forgets about connections when the PPP connection dies, which is remarkably unhelpful when it rains and the DSL restart takes a bit too long. However, instead of resetting connections, it just drops packets (even more unhelpful!).
Sounds like a firewall or routing issue - maybe stale connections get disconnected after a timeout period. Are you using a ping/keepalive inside your protocol.
Otherwise you may ask Wireshark to see what is going on.
First, thanks for many hints - I'm afraid the problem was a completely different one which you couldn't possibly solve by reading my question.
The server application uses log4net, configured with a log file an ImmediateFlush = true. If every log statement is directly written into the file and multiple socket connections occur this slows down the whole application.
The server needed about a minute to really accept the connection. This was far more than the timeout on clientside. So in the log there was only shown "accepted" followed by "disconnected" - even the log was delayed!
Sorry for the inconvenience...
Have you tried changing the backlog and then see how much time or how many clients are served before this problem occurs
You don't say what Windows versions you're using for the server, but you should be aware that the Windows TCP/IP stack behaves differently in server and client OSes. There are limits on how many simultaneous incoming connections a client OS will allow, and they are significantly lower than you might expect.
What do the logs look like from the client side?
Since the error is stating that the client is dropping the connection; if you see the same error on the client side then it is a firewall or proxy that is dropping the connection (both side seeing the opposite side dropping the connection is indicative of a proxy/firewall).
If the error is not present on the client side; then I would say that your client side is where you will see the actual error.
I have a Flex client using a Flash binary (TCP) socket for communication with a Java server. I have a localhost (Apache) server providing a crossdomain.xml file which is wide open just while I am testing.
My code successfully loads the policy file on startup.
I then connect the socket to the server without any difficulty and send a message and get a response. All good so far.
However, when I send a second message through the same socket I get a pause of about 12 seconds then a sandbox violation error:
Security Error: Error #2048: Security sandbox violation: file:///C:/apache_root/ttt1/ttt1.swf cannot load data from localhost:45455.
This is the same port and socket through which the first message succeeded.
I tried re-loading the policy file before every send, but I get the same result.
Any idea why this might be happening? I clearly have an open socket at one point. I am flushing the socket after each send and I tried doing that after each read as well, but the same result.
Thanks in advance
EDIT:
If I recreate the socket prior to every call my code works. I am struggling to believe that this is correct, but maybe there is a Socket setting I am missing.
As far as I know if you're doing binary sockets the crossdomain.xml is not loaded via http.
Have you checked your apache's access logs if the crossdomain is even queried?
You might get connection from flash via tcp from flash asking for the file on your java server (not using http. It just sends the string "" or similar). Look out for them. If you don't answer them within 3 seconds (or so) flash throws an sandbox violation.
The first thing you have to do when you want to make a socket connection is to load the policy file. This only has to be done once per load of the SWF.
Security.allowDomain(host);
Security.loadPolicyFile("xmlsocket://"+host+":"+port);
The request will be made on the assigned port(45455 in your case) your server will have to listen on that port for a request "<policy-file-request/>" without the quotes.
When that request is found then you need to return to the client the crossdomain.xml
with node <allow-access-from domain="*" to-ports="*" />
After the cross domain is sent you need to close the socket on the server side
On the client side you need to ignore the domain response as Flex will handle that however at that time you can reconnect to the socket server.
At this time you can do your data send/receive.
I have a feeling the reason it actually worked for you is because you were using the connection for the policy file to transmit your data before it timed out.
I would suggest reading up on the new style of crossdomain policies and also reading up on the protocol you are using for your socket server
I think it depends on the sandbox-policy you used in the compilation process of your swf not on your crossdomain.xml... maybe this docu helps you:Security sandboxes
But I'm not 100% sure
This sort of sounds like a cache problem. Perhaps you're pulling the first socket connection out of cache and the second one gets rejected because it's getting a 200 from the server.
You might want to add localhost to your flash security exceptions list for debugging. that will quiet the sandbox errors until you get your piece to it's production environment.