Handling network errors in grpc-java - grpc

How can I implement a strategy to detect and try to recover from network errors using gRPC-java? I know that UNAVAILABLE status can mean a network error, but that doesn't tell me what kind of network error it was - and UNAVAILABLE can also be sent back from the server.
In Java RMI we are admonished to pay attention to network problems and we can distinguish e.g. a ConnectionException which is a connection refused error. How can we do this with gRPC?

You can know more details about the error from the cause and description of the Status. For example: if it is a connection error from client side, the cause probably will be an IO/SocketException; if it is a GO_AWAY sent from the server, the description will include the HTTP/2 error code.

Related

Continuously running send pipeline instance

An instance of a BizTalk send pipeline has started to run continuously. On 09/12/2021 an attempt was made to send a file via SFTP, which retried several times but ultimately failed due to a network issue. The error from the event logs is:
The adapter failed to transmit message going to send port "Deliver Outgoing - SFTP" with URL "sftp://xxx.xxxxxx.co.nz:22/To_****/%SourceFileName%". It will be retransmitted after the retry interval specified for this Send Port. Details:"WinSCP.SessionRemoteException: Network error: Software caused connection abort.
For some reason BizTalk made another send attempt at 1:49pm on 10/12/2021 which succeeded as confirmed by the administrator of the SFTP site. Despite this, BizTalk continued making intermittent send attempts and the pipeline instance is still running. The same file has been sent 4 times to the SFTP server.
The pipeline instance in theory should have suspended at 9:47pm on 09/12/2021. I have been able to confirm definitively whether anybody resumed it, but it seems unlikely at this stage. In any case, after sending successfully the pipeline instance should have terminated and should not be re-executing intermittently.
Does anybody know what could account for this behaviour? This is occurring on BTS2020 with CU2 applied.
I've sent messages over SFTP where the WinSCP interpretation of the date-modified attribute doesn't work with a specific type of SFTP server.
With the WinSCP GUI a dialogue box appears and you can disregard this error, but this option isn't available with BizTalk's GUI. This error appears when a file with the same filename already exists on the server and is supposed to be overwritten.
My solution was to create a pipeline component that removed %SourceFileName% on the server. The pipeline component (just like WinSCP GUI) can disregard the modified-date.

BizTalk 2013 AS/2 issues

Currently I'm working on a project on which I need to send a PDF file over AS/2 using BizTalk.
Now, everything is setup in BizTalk.
However, I have an error message in BizTalk saying the following:
The receive pipeline:"Microsoft.BizTalk.EdiInt.DefaultPipelines.AS2Receive,
Microsoft.BizTalk.Edi.EdiIntPipelines, Version=3.0.1.0, Culture=neutral,
PublicKeyToken=31bf3856ad364e35" is trying to suspend a message received on Receive
Location:"/xxx/BTSHTTPReceive.dll". The Adapter/Receive Location however is configured
to never suspend messages on failure. Please change either the receive location or
receive adapter's configuration or the pipeline's configuration.
If I configure the adapter to suspend messages on failure it does work partially. However, I want to get it working with this setup. Is there any way to figure our why my messages are being suspended?
The warning message that follows on the error is the following:
The adapter failed to transmit message going to send port "SendPDFToxxxxOverAS2" with
URL "http://localhost/xxxx/BTSHTTPReceive.dll". It will be retransmitted after the retry
interval specified for this Send Port. Details:"The remote server returned an error:
(500) Internal Server Error.".
I hope someone can make some things clear.
In order to make narrow down the search, I've also removed the checkbox to send and request MDN's in the agreement.
I've found the issue myself.
"Return correlation handle on success" should be off.
"Suspend failed requests" should be on.
Thanks for the help anyway.
Kr

network error (Tcp error)

I am inside a network where I need proxy settings to access the internet.
I have a weird problem.
The internet is working fine.
But it is one particular instance when i get this error:
Network Error (tcp_error)
A communication error occurred: "Operation timed out"
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.
For assistance, contact your network support team.
This happens when I use hadoop in local mode.
I can access the UI interface. I can see the jobs running. but when I try to see the logs of each task.. i am not able to access those logs.
UI--> job-->map--> task--> all <-- this is where the error is..
Any clues?
THanks
Not sure about exactly what your tcp action is, or about Hadoop or your proxy setup, but if you can reliably repeat the error, and the timeout error happens at approximately the same time each time you test, and that time is on the order of minutes, my guess would be that you've got a true processing delay (perhaps caused by blocking somewhere) at the server, but not necessarily.

Service not available, closing transmission channel. The server response was: 4.4.2 Timeout while waiting for command

I'm trying to send a message and we sometime get this error :
Service not available, closing transmission channel. The server response was: 4.4.2 Timeout while waiting for command.
Anyone know what to do with this? Because it only happens "sometime" and apperently, for no specific reason.
I saw many article saying :
442 The server started to deliver the message but then the connection was broke (Source : http://www.sorkincomputer.net/SMTP%20errors.htm)
This is typically a server side (the SMTP server you're delivering to) error or a network connectivity error. There isn't anything you can do about it via your code, you would need to get the related IT staff involved to figure out why your connection is getting closed or interrupted.

Sandbox violation on second socket send

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.

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