I have this EM http code:
require 'eventmachine'
require 'em-http'
require 'json'
http = EM::HttpRequest.new("api_url", :keepalive => true, :connect_timeout => 0, :inactivity_timeout => 0)
EventMachine.run do
s = http.get({'accept' => 'application/json'})
s.stream do |data|
puts data
end
s.errback do
puts "FATAL EM STOPPED: #{response.error}"
EM.stop
end
end
I want to get notified if the connection is lost. I just tried to disable my WIFI and nothing is triggered. After I enable my WIFI the connection is established again and the messages are printed again. I want this behavior I just want to catch that the connection is lost, so that I can raise a error message.
Related
I have this pattern:
channel ESANTE_MPI_CREATE_PATIENT_LISTENER (with a MLLP listener) calls channel ESANTE_MPI_CREATE_PATIENT that calls a TCP destination.
If connection cannot be done in the TCP destination inside ESANTE_MPI_CREATE_PATIENT then this channel reports an error for this destination:(ERROR: ConnectException: Connection refused (Connection refused))
The response transformer does not seem to be called (which is normal as there is no response).
I wonder how I can report the error back to the calling channel ESANTE_MPI_CREATE_PATIENT_LISTENER ?
PS: When tcp destination responds, then I use the response transformer to parse the received frame and create a response message (json error/ok) for the calling channel. Everything works fine here.
My question ends up with: How to trap a Connection refused in a TCP destination to create a response message.
I finally managed this by using the postprocessor script in ESANTE_MPI_CREATE_PATIENT to get the response of the connector and then force a message.
// fake error message prepared for connection refused.
// we put this as the response of the channel destination in order to force a understandable error message.
const sErrorMsg = {
status: "error",
error: "connection refused to eSanté MPI"
};
const TCP_CONNECTOR_ESANTE_MPI_RANK = 2; // WARNING: be sure to take the correct connector ID as displayed into destination.
const TCP_CONNECTOR_ESANTE_MPI_DNAME = 'd' + TCP_CONNECTOR_ESANTE_MPI_RANK; // WARNING: be sure to take the correct connector ID as displayed into destination.
/*
var cms = message.getConnectorMessages(); // returns message but as Immutable
responses. not what we want: we use responseMap instead.
var key = TCP_CONNECTOR_ESANTE_MPI_RANK;
logger.debug(" Response Data=" + cms.get(key).getResponseData());
logger.debug(" Response Data0=" + cms.get(key).getResponseError());
logger.debug(" Response Data1=" + cms.get(key).getResponseData().getError());
logger.debug(" Response Data2=" + cms.get(key).getResponseData().getMessage());
logger.debug(" Response Data3=" + cms.get(key).getResponseData().getStatusMessage());
logger.debug(" Response Data4=" + cms.get(key).getResponseData().getStatus());
*/
var responseMPI = responseMap.get(TCP_CONNECTOR_ESANTE_MPI_DNAME); // return a mutable reponse :-)
if (responseMPI.getStatus()=='ERROR' &&
responseMPI.getStatusMessage().startsWith('ConnectException: Connection refused')) {
// build a error message for this dedicated case
logger.error("connection refused detected");
responseMPI.setMessage(JSON.stringify(sErrorMsg)); // force the message to be responsed.
}
return;
I have a program which connects to a bunch of hosts and checks if they are "socket reflectors". Basically, it is scanning a bunch of ips and doing this:
Connect, check - if there is data, is that data the same as what I am sending? Yes, return true, no return false. No data, return false.
For some reason, asyncio is not reliably closing TCP connections after they time out. I attribute this to the fact that a lot of these hosts I am connecting to are god knows what, and maybe just buggy servers. Be that as it may, there must be a way to make this force timeout? When I run this, it hangs after a while. Out of 12,978 hosts, about 12,768 of them complete. Then I end up with a bunch of open ESTABLISHED connections! Why does this happen?
I need it close the connection if nothing happens during the given timeout period.
async def tcp_echo_client(message, host_port, loop, connection_timeout=10):
"""
Asyncio TCP echo client
:param message: data to send
:param host_port: host and port to connect to
:param loop: asyncio loop
"""
host_port_ = host_port.split(':')
try:
host = host_port_[0]
port = host_port_[1]
except IndexError:
pass
else:
fut = asyncio.open_connection(host, port, loop=loop)
try:
reader, writer = await asyncio.wait_for(fut, timeout=connection_timeout)
except asyncio.TimeoutError:
print('[t] Connection Timeout')
return 1
except Exception:
return 1
else:
if args.verbosity >= 1:
print('[~] Send: %r' % message)
writer.write(message.encode())
writer.drain()
data = await reader.read(1024)
await asyncio.sleep(1)
if data:
if args.verbosity >= 1:
print(f'[~] Host: {host} Received: %r' % data.decode())
if data.decode() == message:
honeypots.append(host_port)
writer.close()
return 0
else:
filtered_list.append(host_port)
print(f'[~] Received: {data.decode()}')
writer.close()
return 1
else:
filtered_list.append(host_port)
writer.close()
if args.verbosity > 1:
print(f'[~] No data received for {host}')
return 1
What am I doing wrong?
Does Mongoid has any method like ActiveRecord::Base.connected??
I want to check if the connection that's accessible.
We wanted to implement a health check for our running Mongoid client that tells us whether the established connection is still alive. This is what we came up with:
Mongoid.default_client.database_names.present?
Basically it takes your current client and tries to query the databases on its connected server. If this server is down, you will run into a timeout, which you can catch.
My solution:
def check_mongoid_connection
mongoid_config = File.read("#{Rails.root}/config/mongoid.yml")
config = YAML.load(mongoid_config)[Rails.env].symbolize_keys
host, db_name, user_name, password = config[:host], config[:database], config[:username], config[:password]
port = config[:port] || Mongo::Connection::DEFAULT_PORT
db_connection = Mongo::Connection.new(host, port).db(db_name)
db_connection.authenticate(user_name, password) unless (user_name.nil? || password.nil?)
db_connection.collection_names
return { status: :ok }
rescue Exception => e
return { status: :error, data: { message: e.to_s } }
end
snrlx's answer is great.
I use following in my puma config file, FYI:
before_fork do
begin
# load configuration
Mongoid.load!(File.expand_path('../../mongoid.yml', __dir__), :development)
fail('Default client db check failed, is db connective?') unless Mongoid.default_client.database_names.present?
rescue => exception
# raise runtime error
fail("connect to database failed: #{exception.message}")
end
end
One thing to remind is the default server_selection_timeout is 30 seconds, which is too long for db status check at least in development, you can modify this in your mongoid.yml.
I have some code use libev on how to deal with connection timeout as below (please refer to http://lists.schmorp.de/pipermail/libev/2011q2/001365.html):
sd = create_socket()
set_socket_nonblock(sd)
connect("127.0.0.1", port) // connect to an invalid port
ev_io_init(&w_io, connect_cb, sd, EV_WRITE)
ev_io_start(...)
ev_timer_init(&w_timer, timeout_cb, 5.0, 0)
ev_timer_start(...)
and in someplace perform ev_run. The connect_cb is called and in this callback function I checked the revents with EV_ERROR, the result is no error. This is strange because I provide an invalid port number which is not listening in local machine. Anyway, I try to send a message in the connect_cb function, got an error 111, which means that connection refused. I'm confused! How to check if the connection is established correctly when use non-block socket?
getsockopt is possible way to get if the connection has some error happen:
int err;
socklen_t len = sizeof(err);
getsockopt(sd, SOL_SOCKET, SO_ERROR, &err, &len);
if (err) {
// error happen
} else {
connection is OK
}
I am trying to pre-bind an XMPP session via XMPHP and pass the rid/sid/jid to a strophe client to attach to the session.
connection code here:
$conn = new CIRCUIT_BOSH('server.com', 7070, $username, $pass, $resource, 'server.com', $printlog=true, $loglevel=XMPPHP_Log::LEVEL_VERBOSE);
$conn->autoSubscribe();
try{
$conn->connect('http://xmpp.server.com/http-bind', 1, true);
$log->lwrite('Connected!');
}catch(XMPPHP_Exception $e){
die($e->getMessage());
}
I am getting the rid and sid but the fulljid in the $conn object stays empty and I cant see a session started on my openfire admin console.
If I create the jid manually by using the given resource and passing jid/rid/sid to strophe to use in attach, I get the ATTACHED status and I see calls from the client to the BOSH ip but I still dont see a session and I cant use the connection.
Strophe Client Code:
Called on document ready:
var sid = $.cookie('sid');
var rid = $.cookie('rid');
var jid = $.cookie('jid');
$(document).trigger('attach', {
sid: sid,
rid: rid,
jid: jid,
});
$(document).bind('attach', function (ev, data) {
var conn = new Strophe.Connection(
"http://xmpp.server.com/http-bind");
conn.attach(data.jid, data.sid, data.rid, function (status) {
if (status === Strophe.Status.CONNECTED) {
$(document).trigger('connected');
} else if (status === Strophe.Status.DISCONNECTED) {
$(document).trigger('disconnected');
} else if (status === Strophe.Status.ATTACHED){
$(document).trigger('attached');
}
});
Object.connection = conn;
});
I think the problem starts on the XMPPHP side which is not creating the session properly.
'attached' is triggered but never 'connected', is status 'connected' supposed to be sent?
What am I missing?
Ok, solved, I saw that XMPPHP lib didn't create a session at all on the openfire server, so I wrote a simple test for the XMPP class which was good and created the session, and for the XMPP_BOSH class that didn't manage create one. Then I saw the issue report here: http://code.google.com/p/xmpphp/issues/detail?id=47 comment no.9 worked, it fixed the issue by copying the processUntil() function from the XMLStream.php to BOSH.php, still can't figure out why this is working. Then I found I had an overlapping bug also with some of the passwords set for users on the openfire server. These passwords contained these ! # % ^ characters, for some reason the XMPP_BOSH is sending the password corrupted or changed so I got Auth Failed exception. Changing the password fixed the issue and I can now attach to the session XMPPHP created with the Strophe.js library.