Could you please provide more details about errors and exceptions:
What the difference between error and blocking exception for target device? What intent and what kind of response should we use in each case? Could you provide the examples?
Should we use ONLY errors codes in EXECUTE response? Are exceptions codes not available in EXECUTE response?
Can exceptions codes be used ONLY in QUERY response, which provides the status of the target device and all associated devices?
How should we handle blocking error of target device if desired error message is provided in the list of exceptions codes and there is no similar message in errors codes (for example, “inSoftwareUpdate”)? Could you please provide an example?
A couple notes from the documentation on this point:
You should return an error code when an issue causes an execute or query request to fail.
You should return an exception when there is an issue or alert associated with a command.
To help clarify this a bit more, an ERROR generally occurs when you are unable to process the intent (can't reach the device, device is already in the expected state, etc.). An EXCEPTION is typically a related state that doesn't necessarily indicate failure (I was able to lock the door, but FYI the battery is low). This can also be the state of another device when used with the StatusReport trait.
You can return either status where appropriate in response to an intent. See the reference pages for QUERY and EXECUTE intents for more details.
Related
I have a question, I would like to know whether ConectionRequest returns response code is 502 or 0 when internet connection lost during the query on Mobile device. Testing Tool returns 502 when there is no internet and debugging the code in Simulator returns response code 0. I would like to know what would be the response code when there is no connectivity during network call. Please advise.
Also, is there a better method to detect offline mode during the network call. I'm aware of Connectivity lib already.
Thanks
This will behave in an inconsistent way because the underlying platforms behave very differently. You need to test for positive responses e.g. server returned 200 instead of testing for negative outcome such as error codes.
You should get an error response callback but we can't guarantee it.
I am executing the ipmimonitoring-sensors.c example provided in the freeipmi library.
It throws internal error sometimes. Issue is reproducible when i execute the program back to back couple of times. I need to wait approximately 30 sec after the last execution for the program to run properly. Has anyone faced this issue before? If yes, can you tell me how to avoid it.
This is the error ipmi_monitoring_sensor_readings_by_record_id: internal error
Thanks
FreeIPMI maintainer here. The "internal error" indicates some logical error that the library doesn't know how to handle. Given its coming from ipmi_monitoring_sensor_readings_by_record_id and it occurs when you run the program back to back, I would bet there is some internal IPMI issue on your system.
Perhaps the motherboard has some issue with a high amount of IPMI traffic or a sensor has issues with a high number of requests. Many of these situations are handled more gracefully (perhaps give a BUSY error or minimally SYSTEM error), but perhaps there is some combo of error situations I haven't yet seen. (Lots of motherboards return errors that would be considered non-standard or unexpected).
If you're interested in working through that, just send something onto the FreeIPMI mailing list.
Set the driver_type = -1 (for default) and it works.
We recently developed an application which will run a query in DB2 and send a mail to the corresponding recipient. It works well in our local system and QA region. But in production, few queries failed (even if it's rare, like once in week). It throws the exception below.
Exception InnerDetails:
ERROR [40003] [IBM][CLI Driver] SQL30081N A communication error has
been detected. Communication protocol being used: "TCP/IP".
Communication API being used: "SOCKETS". Location where the error was
detected: "111.111.111.111". Communication function detecting the
error: "recv". Protocol specific error code(s): "10004", "", "".
SQLSTATE=08001
Since error occurs only in production and not very often, we are not sure whether it is the code or a setting issue. Do you have any idea?
We recently discussed this issue with our IBM rep. After looking in their internal knowledge base, he suggested we add "Interrupt=0" to our connection string, based on recommendations given to other customers that had the same problem.
The default value for Interrupt was 1 before v10.5 FP2 and still is for most connections. They changed the default value to 2 for connections to z/OS (mainframe) in FP2.
We're using C# and the connection string properties for the IBM Data Server Driver for .Net can be found here. I'm sure there is a similar property for their drivers for other languages.
This page from the IBM docs goes into a bit more detail about the setting.
We haven't seen the issue since we recently added the property, but it was always intermittent so I can't yet confidently say that the problem is fixed. Time will tell...
That particular error (SQL30081N) is just a generic message that indicates a network issue between your DB2 client and the server. In this case, you want to look at the Protocol specific error code(s). Here, it looks like you're on Windows, and that particular code (10004) isn't given in the IBM documentation.
So, if you google "windows network error codes", you'll find this page, which says:
WSAEINTR
10004
Interrupted function call.
A blocking operation was interrupted by a call to WSACancelBlockingCall.
Which links to this page with more information on that specific function (emphasis mine):
The WSACancelBlockingCall function has been removed in compliance
with the Windows Sockets 2 specification, revision 2.2.0.
The function is not exported directly by WS2_32.DLL and Windows
Sockets 2 applications should not use this function. Windows Sockets
1.1 applications that call this function are still supported through the WINSOCK.DLL and WSOCK32.DLL.
Blocking hooks are generally used to keep a single-threaded GUI
application responsive during calls to blocking functions. Instead of
using blocking hooks, an applications should use a separate thread
(separate from the main GUI thread) for network activity.
I'm guessing that your application may be blocking for a longer time in your production application than your other environments, and something along the way is causing the interrupt.
Hopefully this leads you down the right path...
I spent hours to solve the same problem and fixed it. I use a Windows exe (developed with C#.NET) to run a SELECT query from a DB2 database and I sometimes got this error. Finally I realized that my problem is a time out error. Error with protocol code "10004" message, sometimes occurs if query execution is longer than 30 seconds which is default timeout value. Maybe the interruption call on the "Windows Socket Error Codes" page occurs for time out mechanism. I add aline to set an acceptable timeout value and got rid off this annoying error. I hope it helps other.
Here is my code fix :
...
connDb.Open();
DB2Command cmdDb = new DB2Command(QueryText,connDb);
cmdDb.CommandTimeout = 300; //I added this line.
using (DB2DataReader readerDb = cmdDb.ExecuteReader())
{
...
I am testing my WPF application connecting to Azure Blob Storage to download a bunch of images using TPL (tasks).
It is expected that in Live environment, there will be highly transient connection to the internet at deployed locations.
I have set Retry Policy and time-out in BlobRequestOptions as below:
//Note the values here are for test purposes only
//CloudRetryPolicy is a custom method returning adequate Retry Policy
// i.e. retry 3 times, wait 2 seconds between retries
blobClient.RetryPolicy = CloudRetryPolicy(3, new TimeSpan(0, 0, 2));
BlobRequestOptions bro = new BlobRequestOptions() { Timeout = TimeSpan.FromSeconds(20) };
blob.DownloadToFile(LocalPath, bro);
The above statements are in a background task that work as expected and I have appropriate exception handling in background task and the continuation task.
In order to test exception handling and my recovery code, I am simulating internet disconnection by pulling out the network cable. I have hooked up a method to System.Net.NetworkChange.NetworkAvailabilityChanged event on UI thread and I can detect connection/disconnection as expected and update UI accordingly.
My problem is: If I pull the network cable while a file is being downloaded (via blob.DownloadToFile), the background thread just hangs. It does not timeout, does not crash, does not throw exception, nothing!!! As I write, I have been waiting ~30 mins and no response/processing has happened in relation to background task.
If I pull the network cable, before download starts, execution is as expected. i.e. I can see retries happening, exceptions raised and passed ahead and so on.
Has anyone experienced similar behaviour? Any tips/suggestions to overcome this behaviour/problem?
By the way, I am aware that I can cancel the download task on detection of network connectivity loss, but I do not want to do this as network connectivity can get restored within the time-out duration and the download process can continue from where it was interrupted. I have tested this auto resumption and works nicely.
Below is a rough indication of my code structure (not syntactically correct, just a flow indication)
btnClick()
{
declare background_task
attach continuewith_task to background task
start background task
}
background_task()
{
try
{
... connection setup ...
blob.DownloadToFile(LocalPath, bro);
}
catch(exception ex)
{
... exception handling ....
// in case of connectivity loss while download is in progress
// this block is not getting executed
// debugger just sits idle without a current statement
}
}
continuewith_task()
{
check if antecedent task is faulted
{
... do recovery work ...
// this is working as expected if connectivity is lost
// before download starts
// this task does not get called if connectivity is lost
// while file transfer is taking place
}
else
{
.. further processing ...
}
}
Avkash is correct I believe. Also, to be clear, you will basically never see that network removed error so not a lot of point in testing for it. You will see a ton of connection rejected, conflicts, missing resources, read-only accounts, throttles, access denied, even DNS resolution failures depending on how you are handling storage accounts. You should test for those.
That being said, I would suggest you do not use the RetryPolicy at all with blob or table storage. For most of the errors you will actually encounter, they are not retryable to begin with (e.g. 404, 409, 403, etc.). When you have a retry policy in place, it will by default actually try it 4 more times over the next 2 minutes. There is no point in retrying bad credentials for instance.
You are far better off to simply handle the error and retry selectively yourself (timeouts and throttle are about the only thing that make sense here).
Your problem is mainly caused because Azure storage client libraries uses file streaming classes underneath and that why the API hang is not directly related with Windows Azure Blob client library. Calling file streaming API directly over network you can see the exact same behavior when network cable is suddenly removed, however removing network gracefully will return different behavior.
If you search on internet you will find streaming classes does not detect the network loss and that's why in your code you can check the network disconnect event and then stop the background streaming thread.
Im currently developing with WebkitGtk+ Unstable Api
I'm using Soupsession Object to conect Signals and Rertve Soupmessages to (again)
hook signals to every Message to obtain time details of network events, my problem is how to monitor errors from this point.
if I'm using just the signal, there is a way to detect when a network error like DNS error or a socket error ocurrs i searched over the SoupSession Manuals but found nothing usable.
can someone give me some guidances?
Some time ago i figured it out.
the errors are reported in the responce http code of the soup message
https://developer.gnome.org/libsoup/stable/libsoup-2.4-soup-status.html
I just needed to capture the status code in the soup message signal "finished" to know if the resource failed (and why) or if was successful