I use gevent-socketio in my application. I need to get information about user disconnected even if he didn't finish session properly (calling socket.disconnect() from JS.) As I see from docs, SocketIOServer constructoor has parameter *heartbeat_interval*, but I don't see it in code. As I understood, documentation is outdated - its version 0.3.1, but version of code is 0.3.5-rc2 (and it's only available).
How can I set heartbeat timeout in gevent-socketio?
Thanks,
Boris.
Related
I am newbie on Fix in general and I have started from QuickFix to make practice. I apology in advance from the following trivial questions.
I have understood that to handle ExecutionReport I need to use crack() method inside FromApp() and implementing OnMessage().
But what I have two questions :
1) What happens if during a Partially fill order ExecutionReport message suddenly session drops, which is the way to handle this situation. Trying to reconnect and Send a request ? Please Can you provide a simple explanation in steps and what QuickFix Api method should I use ?
2) If I need to implement a FixEngine to handle dropcopy should I be aware of something in particular ?
Thank you for your help
1). Just make sure ResetOnDisconnect parameter is set to N for your trading session: ResetOnDisconnect=N (docs)
QuickFix will be automatically attempting to reconnect every ReconnectInterval seconds;
Once connected (with ResetOnDisconnect=N) it will also automatically exchange last known message sequence numbers with the FIX server, and the ones lost during the disconnection will be re-sent - so without a line of code you will receive the missing messages.
Also, if disconnection was for a longer period of time, you may want to send Order Status Request (H) message to the FIX server to receive actual ExecutionReport for your pending orders.
2) The question is too general for me to answer...
How can I determine what the numeric timeout value is that is causing the below stack trace?
...
File "/usr/lib/python2.7/httplib.py", line 548, in read
s = self._safe_read(self.length)
File "/usr/lib/python2.7/httplib.py", line 647, in _safe_read
chunk = self.fp.read(min(amt, MAXAMOUNT))
File "/usr/lib/python2.7/socket.py", line 380, in read
data = self._sock.recv(left)
timeout: timed out
After importing my modules, the result of socket.getdefaulttimeout() is None (note that this isn't the same situation as what produced the above, since getting those requires an 8-hour stress run on the system).
My code is not setting any timeout values (default or otherwise) AFAICT. I have not yet been able to find any hint that 3rd party libraries are doing so either.
Obviously there's some timeout somewhere in the system. I want to know the numeric value, so that I can have the system back off as it is approached.
This is python 2.7 under ubuntu 12.04.
Edit:
The connection is to localhost (talking to CouchDB listening on 127.0.0.1), so NAT shouldn't be an issue. The timeout only occurs when the DB is under heavy load, which implies to me that it's only when the DB is getting backed up and cannot respond quickly enough to requests, which is why I would like to know what the timeout is, so I can track response times and throttle incoming requests when the response time gets over something like 50% of the timeout.
Not knowing anything more my guess would be that NAT tracking expires due to long inactivity and unfortunately in most cases you won't be able to discover exact timeout value. Workaround would be to introduce some sort of keep alive packets to your protocol if there's such a possibility.
When reading the Sidekiq Wiki I see the following examples:
From Getting started:
Send a message to be processed asynchronously:
HardWorker.perform_async('bob', 5)
You can also send messages by calling the delay method on a class method:
User.delay.do_some_stuff(current_user.id, 20)
Also, from Delayed extensions:
Use delay to deliver your emails asynchronously. Use delay_for(interval) or delay_until(time) to deliver the email at some point in the future.
UserMailer.delay.welcome_email(#user.id)
UserMailer.delay_for(5.days).find_more_friends_email(#user.id)
UserMailer.delay_until(5.days.from_now).find_more_friends_email(#user.id)
So what is actually the difference between perfrom_async and delay? In which situations would I prefer the one over the other?
perform_async is Sidekiq's native API. delay is a compatibility API with DelayedJob. Use perform_async when possible.
I am trying to set a timeout on write operations when using GCDAsyncSocket. The code is pretty simple and is the following.
[iAsyncSocket writeData:bytesToSend withTimeout:3.0 tag:0];
Then I disable the Internet connection on my Mac and wait for write timeout to occur, but nothing happens. I don't get a disconnection with a GCDAsyncSocketWriteTimeoutError error as I should.
I have also validated that my server stops, as expected, receiving the messages after I turn off the Internet connection.
I have looked inside the source code and I have found out that the writeTimer, that is responsible for firing a write timeout event, is always cancelled (function endCurrentWrite is called). Tracing back to where the timer is cancelled, I ended up at the following line of code.
ssize_t result = write(socketFD, buffer, (size_t)bytesToWrite);
The write system call always returns the total number of bytes that I am sending, as if the socket manages to send the data although there is no Internet connection. Is this logical?
Has anyone come up with the same problem or seen similar behaviour? Or has anyone managed to set a write timeout for a GCDAsyncSocket?
Thanks a lot.
I'm writing an internal service that needs to touch a mod_perl2 instance for a long-running-process. The job is fired from a HTTP POST, and them mod_perl handler picks it up and does the work. It could take a long time, and is ready to be handled asynchronously, so I was hoping I could terminate the HTTP connection while it is running.
PHP has a function ignore_user_abort(), that when combined with the right headers, can close the HTTP connection early, while leaving the process running (this technique is mentioned here on SO a few times).
Does Perl have an equivalent? I haven't been able to find one yet.
Ok, I figured it out.
Mod_perl has the 'opposite' problem of PHP here. By default, mod_perl processes are left open, even if the connection is aborted, where PHP by default closes the process.
The Practical mod_perl book says how to deal with aborted connections.
(BTW, for the purposes of this specific problem, a job queue was lower on the list than a 'disconnecting' http process)
#setup headers
$r->content_type('text/html');
$s = some_sub_returns_string();
$r->connection->keepalive(Apache2::Const::CONN_CLOSE);
$r->headers_out()->{'Content-Length'} = length($s);
$r->print($s);
$r->rflush();
#
# !!! at this point, the connection will close to the client
#
#do long running stuff
do_long_running_sub();
You may want to look at using a job queue for this. Here is one provided by Zend that will let you start background processing jobs. There should be a number of these to choose from for php and perl.
Here's another thread that talks about this problem and an article on some php options. I'm not perl monk, so I'll leave suggestions on those tools to others.