I have to implement some error handling logic for DynamoDb errors. As said by AWS documentation, the errors are divided into client and server errors.
May be I am missing something in the object browser, but I don't understand how I will retrieve the "HttpStatusCode StatusCode" for the client errors (AmazonClientException) ?
This is just part of the server errors (AmazonServiceException) only.
As, I need to do some logging based on the error code, it seems that it can not be obtained from client exceptions currently.
There is no status code for a AmazonClientException which is not also an AmazonServiceException. If you have one from the service, it will be of the second type and you can get the status code. If you have one of the first type, it could be because you don't have an internet connection, or the service responded with a malformed response (perhaps not even HTTP, who knows!).
It's a little confusing that they decided to extend AmazonClientException with AmazonServiceException, because it means that (in java) you might have to do something like this:
try {
// ... make some dynamo requests ...
} catch (AmazonServiceException e) {
// aha, I can get at the status code!
} catch (AmazonClientException e) {
// OK, something really bizarre happened... perhaps dynamo is
// down, or I'm having internet issues.
}
Related
When I call Hub method I get frame response:
{"invocationId":"1","type":3,"error":"An error occurred while updating
the entries. See the inner exception for details."}
How can I get detailed error report (row and file where error occurred) without manually debugging and using step over and check where the code raise exception.
On net I found plenty codes where EnableDetailedErrors is used
services.AddSignalR(options =>
{
options.Hubs.EnableDetailedErrors = true;
});
but options (at least in version 1.0.0-alpha2-final) does not have property Hubs.
This is what you need to do in core (not sure the exact version this was added):
// signalR
services.AddSignalR(options =>
{
if (Environment.IsDevelopment()) {
options.EnableDetailedErrors = true;
}
});
It goes without saying that the reason this is disabled by default in production is for security reasons. So be careful not to expose things you may not wish 'hackers' to see in any of the exceptions you may throw.
Implementing the above setting will reveal a more detailed message in the browser console, whcih you can also see in the websocket debugging tab:
Quick tip:
I've set up SignalR twice now on ASPNetCore and I think I've made the same mistake both times:
// from typescript client arguments are passed like this
this.hubConnection.invoke('SendMessage', 'simon', 'hello');
// not like this
this.hubConnection.invoke('SendMessage', ['simon', 'hello']);
Also invoke will wait for a response, while send does not. So you may not see errors using send.
Currently the option to enable detailed errors is not implemented. There is an issue tracking this. My recommendation would be to turn on logging on the server side - the original exception will be logged there.
Using Meteor, the Meteor.loginWithPassword function calls the server, which then returns a User not found error when the user does not exist, or a Match failed when the password does not match the user's password.
Is there an easy way for the server to return the same error (or no error) during both conditions of a failed login?
I don't want hackers to know when they found a valid username or UserID on my system. I don't want the server to say User not found, telling potential hackers when they have (or have not) found a valid user. It would be great if there's an easy way to change the error message the server returns from the accounts-password Meteor module, to harden the security a little bit. I'd like the server's error result to be something generic, like failed or undefined or null, regardless of the reason of the login error.
I know I can probably fork/re-purpose the accounts-password module, but hoping there's something simpler.
Thanks!
Yes, you can place the function somewhere in the /server-folder and change the error message. Like this:
Accounts.validateLoginAttempt(function(options) {
if (!options.allowed) { //that is, if there's an error
throw new Meteor.Error('login-error', 'Error!');
}
//...other code for other purposes below
});
/server/accounts.js
In Apigee, can fault handling - specifying a FaultRule and a RaiseFault policy be used to handle and provide a custom message for:
{
"fault": {
"faultstring": "Not Found",
"detail": {
"errorcode": "CLASSIFICATION_FAILURE"
}
}
}
If this can be done, should the 'Condition' for the fault rule be 'fault.name = "CLASSIFICATION_FAILURE"'? I tried this and it is not working.
CLASSIFICATION_FAILURE is a system level failure to find an API Proxy for the given URL/URI. The request will not even reach the API proxy(hence the policies) - which is the precise complaint by the system.
So you do not want to handle an error like that.
Another way to approach this case is to have a catch all API proxy with basepath /** which will be invoked when there is no specific URL match. You can generate a custom message in this proxy - this can be the message you wanted to send across in case of classification failure.
Srikanth's answer on 30/05/2014 is only partially correct. Using a basepath /** did not work for us. Instead, we had to create an api proxy with basepath = /
Inside the proxy, we defined a RaiseFault in Preflow and that was it.
I have an Apigee proxy that has two resources (/resource1 and /resource2). If tried to access /resource3. How do I return a 404 error instead of the Apigee default fault?
Apigee displays the below fault string:
{
"fault": {
"faultstring": "The Service is temporarily unavailable",
"detail": {
"errorcode": "messaging.adaptors.http.flow.ServiceUnavailable"
}
}
}
Thanks
Currently the way flows work in apigee this way - It parses through your default.xml (in proxy) and tries to match your request with one of the flow either through the path-suffix like "/resource1, /resource2" or VERB or any other condition you might have. If it does not find any matching condition, it throws the error like above.
You can add a special flow which will be kicked in if the condition matches none of the valid flows you have. You can add a raisefault policy in that flow and add a custom error response through that flow.
A better solution is to:
be sure to define something in the base path of all Proxy APIs
create an additional Proxy API called "catchall" with a base path of "/" and with just a Raise fault throwing a 404
Apigee execute Proxy APIs from longest Base Path to shortest; the catchall will run last and always throw back a 404
I just want to clarify Vinit's answer. Vinit said:
If it does not find any matching condition, it throws the error like above.
Actually, if no matching flow condition is found, the request will still be sent through to the backend. The error you mentioned:
{
"fault": {
"faultstring": "The Service is temporarily unavailable",
"detail": {
"errorcode": "messaging.adaptors.http.flow.ServiceUnavailable"
}
}
}
was returned after attempting to connect to the backend without matching a flow.
Vinit's solution to raise a fault to create the 404 is the best solution for your requirements.
In some cases, however, it is appropriate to pass all traffic through to the backend (for example, if you don't need to modify each resource at the Apigee layer, and you don't want to have to update your Apigee proxy every time you add a new API resource). Not matching any flow condition would work fine for that use case.
First off: This is not another question about how to load a policy file.
I have an app in development that connects to a socket server, gets the policy file and works just dandy. However, when the socket server is down for whatever reason, I need to gracefully fallback to an alternative method of getting messages from the server (polling, basically).
This is not a problem, except for one thing:
Error: Request for resource at xmlsocket://[ip]:4770 by requestor from http://[ip]/cooking/Client.swf has failed because the server cannot be reached.
There doesn't appear to be a way to catch this. I have these event listeners on my socket:
addEventListener(Event.CLOSE, closeHandler);
addEventListener(Event.CONNECT, connectHandler);
addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
addEventListener(ProgressEvent.SOCKET_DATA, socketDataHandler);
SecurityErrorEvent is what you might think fires, but it doesn't. The docs say it fires for these reasons:
Local untrusted SWF files may not communicate with the Internet. You can work around this limitation by reclassifying the file as local-with-networking or as trusted.
You cannot specify a socket port
higher than 65535.
In the HTML page that contains the
SWF content, the allowNetworking
parameter of the object and embed
tags is set to "none".
So none of those apply. It appears what I really want to catch is the failure of the policy file to load, but even doing an explicit Security.loadPolicyFile() won't help, since that load is deferred to the first socket request AND doesn't fire any events.
For completeness, I also surrounded the call to connect() with a try{}catch (e:*){}, no result.
There's got to be a way to sort this. Any ideas? I simply need a way to tell when the connection has failed because of networking issues and try an alternate path.
EDIT: Despite my previous tests and the docs, it appears SecurityErrorEvent does fire - only it does it about 20 seconds after the load fails, so it's not obvious. I guess that's as immediate as I'm going to get from Flash.
Don't forget to retry connecting :)
private function onIOError(e:IOErrorEvent):void {
e.stopPropagation();
++this.retryCount;
if( this.retryCount >= 12 ){
this.connectTimer.stop();
this.dispatchEvent( new Event( 'TIMIEDOUT' ) );
}else{
this.err = 'IO-ERROR-EVENT - ' + e.text + '\r\nAttempting to reconnect';
}
}