I am workng on the eventmachine . And needs to restart the servers with port in loop .
I am trying to stop the servers with the code stop_server(#signature) id but if I reconnect it , it gives me error of
/gems/eventmachine-1.0.0/lib/eventmachine.rb:526:in `start_tcp_server': no acceptor (port is in use or requires root privileges) (RuntimeError)
Here is the code
$servers = {}
EventMachine::run {
[1,2,3].each do |port|
$servers[:em_server_id] = EventMachine::start_server "", port, EchoServer, port
restart_server($servers[:em_server_id],port)
end
}
def restart_server(s,port)
EventMachine::stop_server(s)
$servers[:em_server_id] = nil
EventMachine::start_server "", port, EchoServer, port
end
If i get better way sloving restart server that will also help else I need to stop and start servers again in that way only.
Related
So i have this task to log activities to a file, but it has to be done
remotely on the server side, Remote logging.
NOTE : Remote Logging has to be in latest version of Log4j2(2.10)
My task was simple
Send logging info to a port.
Log info from port to a file.
My Discoveries
Socket Appender exist which help send info to a port. This is it, you dont need to create a client side code or anything.
Socket appender configuration in log4j2.properties
appender.socket.type = Socket
appender.socket.name= Socket_Appender
appender.socket.host = "IP address"
appender.socket.port = 8101
appender.socket.layout.type = SerializedLayout
appender.socket.connectTimeoutMillis = 2000
appender.socket.reconnectionDelayMillis = 1000
appender.socket.protocol = TCP
Adapting from here. But this is also log4j 1.x adaptation.
I found out that before log4j 2.6 to listen to a port we used TcpSocketServer which started a server using LogEventBridgeThis helped reach that conclusion. This class was in core.net.server which is no longer available.Assuming it is not used anymore and the only similar/closest class, TcpSocketManager.Other links that helped. How to use SocketAppend?
Then i tried this
public static final Logger LOG=LogManager.getLogger(myapp.class.getName());
main(){
LOG.debug("DEBUG LEVEL");
}
and got the following error
main ERROR TcpSocketManager (TCP:IPAddress:8111) caught exception
and will continue: java.net.SocketTimeoutException: connect timed out
I know this work because i made it read to a socket but there was no one listening, but somehow i messed up big time and there was a code change.
I need help how to go ahead. Thank You in advance
The socket server to remotely receive log events has been moved to a separate repository: https://github.com/apache/logging-log4j-tools
This still needs to be released.
I am using Akka Cluster 2.4.3 and trying to setup a simple cluster in my machine to understand its working better. I have a singleton cluster with remoting enabled with primary and standby master and one worker node. Each of these 3 run in separate JVMs
Things work fine when all the nodes are started the first time. If I kill and restart the worker, I see following issues happening
Restart Worker
When the worker comes back after restart, the master on receiving MemberUp event tries to resolve for the actorRef from the member address the following way
context.actorSelection(member.address.toString).resolveOne(15 seconds)
This fails with an exception saying ActorNotFound. This works with no problem when all the nodes are coming up for the first time in the cluster.
Restart worker again
This time, the worker comes up with the following message
[WARN] [04/15/2016 18:24:24.991] [clustersystem-akka.remote.default-remote-dispatcher-5] [akka.remote.Remoting] Tried to associate with unreachable remote address [akka.tcp://clustersystem#host1:2551]. Address is now gated for 5000 ms, all messages to this address will be delivered to dead letters. Reason: [The remote system has quarantined this system. No further associations to the remote system are possible until this system is restarted.]
Restart worker again
This time the resolveOne on a MemberUp event works.
I am having a bit of difficulty in understanding what is happening here, I have looked into the docs but I did not find anything that will help me in there.
application.conf
akka {
actor {
provider = "akka.cluster.ClusterActorRefProvider"
}
remote {
enabled-transports = ["akka.remote.netty.tcp"]
}
log-dead-letters = off
jvm-exit-on-fatal-error = on
loglevel = "DEBUG"
remote {
log-remote-lifecycle-events = off
netty.tcp {
hostname = "host1"
port = 0
}
}
cluster {
seed-nodes = [
"akka.tcp://clustersystem#host1:2551",
"akka.tcp://clustersystem#host1:2552"]
auto-down-unreachable-after = 10s
}
extensions = ["akka.cluster.metrics.ClusterMetricsExtension"]
}
I start master nodes at ports 2551 and 2552 (provide the ports as command line args) and I start the worker on port 3551
I need my code to handle every kind or error that can be thrown by the Net::OpenSSH module. I can't figure out how to do this using the $ssh->error function.
For example :
switch ($ARGV[2]) {
case "OBS" {
my $ssh = Net::OpenSSH->new("$user:$passwdobs\#$ARGV[1]");
$ssh->error and die "echec ssh : " . $ssh->error;
}
}
This code gives me error messages like this:
ssh: connect to host 126.120.180.250 port 22: Connection refused
echec ssh : unable to establish master SSH connection: bad password
or master process exited unexpectedly at sshscript.pl line 26.
These two error messages have nothing in common, the first tells me the real reason, and the second tells me WHO failed (the master ssh connection). It seems the only errors that OpenSSH can throw are the constants listed here: Net::OpenSSH::Constants
I would like my script to let me know why my connections failed, so I can send the errors to a database with the help of a separate ssh_error.sql file. Is this possible with OpenSSH module ?
I have a standalone lua script that uses lua sockets to connect to a server via TCP IP. It uses receive call to receive data from that server. It works, however, when I try to stop it with Ctrl+C, one of the two scenarios is happening:
-If there is currently no traffic and receive is waiting, Ctrl+C will have no effect. The program will continue to run, and will have to be terminated by kill.
-If there is traffic, the program will exit with the below printout and with the socket still open and with the server not accepting another connection:
lua: luaSocketTest.lua:15: interrupted!
stack traceback:
[C]: in function 'receive'
luaSocketTest.lua:15: in function 'doWork'
luaSocketTest.lua:22: in main chunk
[C]: ?
I tried using pcall to solve the second scenario, without success. pcall doesn't return, the process still throws the error.
Sample of my program is below:
local socket = require ("socket")
local ip = "localhost"
local port = 5003
function doWork ()
print ("Starting socket: "..ip..":"..port)
client = assert(socket.connect(ip, port))
print ("Socket Accepted")
client:send("TEST TEST")
while 1 do
local byte, err = client:receive (1)
if not err then
print (byte)
end
end
end
while 1 do
local status = pcall(doWork())
print ("EXITED PCALL WITH STATUS: "..tostring(status))
if not status then client:close() end
end
This would be quite a change, but you could employ lua-ev. It allows to add Signal handlers, which is exactly what is required to react to ctrl-c.
local socket = require'socket'
-- make connect and send in blocking mode
local client = socket.connect(ip,port)
client:send('TEST TEST')
-- make client non-blocking
client:settimeout(0)
ev.IO.new(function()
repeat
local data,err,part = client:receive(10000)
print('received',data or part)
until err
end,client:getfd(),ev.READ):start(ev.Loop.default)
local ev = require'ev'
local SIGINT = 2
ev.Signal.new(function()
print('SIGINT received')
end,SIGINT):start(ev.Loop.default)
ev.Loop.default:loop()
I'm trying to send some data in bits from one computer to another one that are on the same network using TCP in Matlab.
Currently this is what I have setup to open the connections. I'm trying to simulate a peer-to-peer connection because they need to send and receive data from each other. It works fine on my local machine when I run it using my IPv4 and IPv6.
%code starts in one file
openRecieve('0.0.0.0', 3000); %accept all connections
openSend('10.32.41.235',3000);
Then I do the same in another file and I can run them i parallel on my machine:
%code starts in other file
openSend('10.32.41.235',3000); %IPv4 of PC
openRecieve('0.0.0.0', 3000); %accept all connections
The IPs are bogus...... This code works on my machine when run with 2 different instances of matlab open. However it doesn't work between 2 different computers.
Code for openReceive:
function connectionServer = openRecieve(client, port)
t = tcpip('0.0.0.0', port, 'NetworkRole', 'Server');
set(t, 'InputBufferSize', 3000000);
% Open connection to the client.
fopen(t);
fprintf('%s \n','Client Connected');
connectionServer = t;
set(connectionServer,'Timeout',.1);
end
Code for openSend:
function connectionSend = openSend(host, port)
d = tcpip(host, port, 'NetworkRole', 'Client');
set(d, 'OutputBufferSize', 3000000); % Set size of receiving buffer, if needed.
%Trying to open a connection to the server.
while(1)
try
fopen(d);
break;
catch
fprintf('%s \n','Cant find Server');
end
end
connectionSend = d;
end
Any help is appreciated.
It is now running although the only thing I changed was the port numbers from 3000 and 3000 to 3000 and 3001.......... Also using only IPv4 was pretty key as my network didn't allow for IPv6.
For anyone trying to write TCP code in Matlab just use '0.0.0.0' for the connection if you don't care who is connecting as it will accept all IPs trying to connect on that port #.
Current code for first file:
sConec = openSend('10.234.24.124', 3000); %IPv4 Address of comp your trying to connect to
rConec = openRecieve('0.0.0.0', 3001); %Accept all connections
Current code for second file:
rConec = openRecieve('0.0.0.0', 3000); %Accept all connections
sConec = openSend('10.109.22.142', 3001); %IPv4 Address of computer your trying to connect to