I have lost connection to Cassandra server and I am not able to restore it back.
When I run: sudo service cassandra status I can see service is running:
● cassandra.service - LSB: distributed storage system for structured data
Loaded: loaded (/etc/init.d/cassandra; generated; vendor preset: enabled)
Active: active (exited) since Fri 2018-04-27 13:06:21 UTC; 4min 5s ago
Docs: man:systemd-sysv-generator(8)
Process: 18479 ExecStop=/etc/init.d/cassandra stop (code=exited, status=0/SUCCESS)
Process: 18539 ExecStart=/etc/init.d/cassandra start (code=exited, status=0/SUCCESS)
Tasks: 0 (limit: 4915)
CGroup: /system.slice/cassandra.service
Apr 27 13:06:21 serveur-1 systemd[1]: Starting LSB: distributed storage system for structured data...
Apr 27 13:06:21 serveur-1 systemd[1]: Started LSB: distributed storage system for structured data.
But When I run > cqlsh, I got the following:
Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
Deleting content of directory /var/lib/cassandra/commitlog and restarting cassandra fixed my issue !
Check that Cassandra really accepts connections through loopback interface.
See what's in your cassandra.yaml under listen_address and listen_interface property
# cat /etc/cassandra/cassandra.yaml | grep listen
...
listen_address: 172.17.0.2
...
If you see a non local address, it might happen that cqlsh needs to connect through another interface to your Cassandra instance. Try this command (by replacing the IP with the same IP in configuration:
# cqlsh 172.17.0.2
You can check which hosts are allowed co access your Cassandra service using the following command
# netstat -l
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 localhost:7199 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:9042 0.0.0.0:* LISTEN
tcp 0 0 localhost:38899 0.0.0.0:* LISTEN
tcp 0 0 20f1802:afs3-fileserver 0.0.0.0:* LISTEN
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node Path
0.0.0.0 means that my Cassandra instance allows connection from both loopback and ethernet interface.
Delete all content from commitlog and it will work.
Related
I created web server using node.js in CentOS 8.
But It doesn't work.
This is my node.js web server.
const http = require('http');
const hostname = '0.0.0.0';
const port = '8080';
httpd = http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end('Hello World!');
});
httpd.listen(port, hostname, function(){
console.log('Server Start');
});
I sent ping to centos for port 22 and 8080.
I couldn't receive response for only port 8080.
C:\Users\user>tcping -p 22 <centOS IP>
Probing <centOS IP>:22/tcp - Port is open - time=14.019ms
Probing <centOS IP>:22/tcp - Port is open - time=13.159ms
Probing <centOS IP>:22/tcp - Port is open - time=8.601ms
Probing <centOS IP>:22/tcp - Port is open - time=9.896ms
C:\Users\user>tcping -p 8080 <centOS IP>
Probing <centOS IP>:8080/tcp - No response - time=2010.980ms
Probing <centOS IP>:8080/tcp - No response - time=2008.277ms
Probing <centOS IP>:8080/tcp - No response - time=2008.509ms
Probing <centOS IP>:8080/tcp - No response - time=2000.949ms`
I cheked below info.
(I checked listening port 8080)
(I turned off the firewalld, iptables...)
<Linux>
[opc#instance-20220607-1056 webTest]$ netstat -tnlp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:9003 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
.
.
[opc#instance-20220607-1056 webTest]$ sudo service iptables status
Redirecting to /bin/systemctl status iptables.service
Unit iptables.service could not be found.
[opc#instance-20220607-1056 webTest]$ sudo systemctl status nftables
nftables.service - Netfilter Tables
Loaded: loaded (/usr/lib/systemd/system/nftables.service; disabled; vendor p>
Active: inactive (dead)
Docs: man:nft(8)
lines 1-4/4 (END)
[opc#instance-20220607-1056 webTest]$ sudo systemctl status firewalld
firewalld.service
Loaded: masked (Reason: Unit firewalld.service is masked.)
Active: inactive (dead)
Jan 05 17:49:52 instance-20220607-1056 systemd[1]: Starting firewalld - dynamic firewall daemon...
Jan 05 17:49:54 instance-20220607-1056 systemd[1]: Started firewalld - dynamic firewall daemon.
Jan 05 17:49:54 instance-20220607-1056 firewalld[1480]: WARNING: AllowZoneDrifting is enabled. This is consi>
Jan 05 20:38:06 instance-20220607-1056 systemd[1]: Stopping firewalld - dynamic firewall daemon...
Jan 05 20:38:10 instance-20220607-1056 systemd[1]: firewalld.service: Succeeded.
Jan 05 20:38:10 instance-20220607-1056 systemd[1]: Stopped firewalld - dynamic firewall daemon.
[opc#instance-20220607-1056 webTest]$ sudo lsb_release -a
LSB Version: :core-4.1-amd64:core-4.1-noarch
Distributor ID: OracleServer
Description: Oracle Linux Server release 8.7
Release: 8.7
Codename: n/a
What more should I check?
Thank you for your answer.
This issues occurred for Oracle cloud setting
I solved this problem by referring to the link below.
link
Mongo up and running on CentOs Machine
All IPs enabled, no authorization
# network interfaces
net:
port: 27017
bindIp: 0.0.0.0
# security: none
# authorization: 'enabled
Port enabled
netstat -tulnp
(No info could be read for "-p": geteuid()=1001 but you should be root.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:5432 0.0.0.0:* LISTEN -
Connection from the server itself using the IP works fine
mongo --host 10.X.X.16
MongoDB shell version v4.2.2
connecting to: mongodb://10.X.X.16:27017/?compressors=disabled&gssapiServiceName=mongodb
MongoDB server version: 4.2.2
Server has startup warnings:
2020-01-21T15:48:26.297-0800 I CONTROL [initandlisten]
Doing the same thing from a remote Windows Machine
mongo --host 10.X.X.16
MongoDB shell version v4.2.1
connecting to: mongodb://10.X.X.16:27017/?compressors=disabled&gssapiServiceName=mongodb
2020-01-21T15:59:07.563-0800 E QUERY [js] Error: couldn't connect to server 10.65.5.16:27017, connection attempt failed: NetworkTimeout: Error connecting to 10.X.X.16:27017 :: caused by :: Socket operation timed out :
connect#src/mongo/shell/mongo.js:341:17
#(connect):2:6
2020-01-21T15:59:07.571-0800 F - [main] exception: connect failed
2020-01-21T15:59:07.571-0800 E - [main] exiting with code 1
Thanks!
Problem fixed:
I had to disable the firewall for the mongo port
sudo firewall-cmd --zone=public --add-port=27017/tcp --permanent
sudo firewall-cmd --reload
After installing and starting mongodb on Google Ubuntu instance I can verify that 'mongodb' is running with: sudo systemctl status mongodb:
● mongodb.service - LSB: An object/document-oriented database
Loaded: loaded (/etc/init.d/mongodb; generated; vendor preset: enabled)
Active: active (running) since Mon 2017-02-27 19:41:17 UTC; 57min ago
Docs: man:systemd-sysv-generator(8)
Tasks: 13 (limit: 4915)
Memory: 71.7M
CPU: 14.520s
CGroup: /system.slice/mongodb.service
└─1914 /usr/bin/mongod --config /etc/mongodb.conf
Feb 27 19:41:15 instance-1 systemd[1]: Starting LSB: An object/document-oriented database...
Feb 27 19:41:16 instance-1 mongodb[1827]: * Starting database mongodb
Feb 27 19:41:17 instance-1 mongodb[1827]: ...done.
Feb 27 19:41:17 instance-1 systemd[1]: Started LSB: An object/document-oriented database.
It all looks good. But by some reason another application running on the same machine is not able to connect to the what-seems-to-be-running-properly mongodb.
Running nmap 127.0.0.1 returns:
PORT STATE SERVICE
22/tcp open ssh
631/tcp open ipp
There is no mongodb's port # 27017 listed there as *open*.
Interesting that the firewall is disabled. How can I assure themongodbport27017` is open and available to other applications?
nmap scan all common port, mongodb use port 27017 by default which is not listed in default nmap default port scan. On the other hand, you can specify the port manually :
nmap -p 27017 127.0.0.1
You will get :
PORT STATE SERVICE
27017/tcp open unknown
If you see STATE close, this means mongodb is not running and then you should begin to worry about it
Or as suggested by #Dimitri using netstat such as :
netstat -tulpn
which gives :
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN -
I'm using a Linux VM (Ubuntu 15.10) to spin up a Postgres Database, and as far as I can tell, everything should be configured right.
My firewall is disabled:
user#UBUNTUMACHINE:~$ sudo ufw status numbered Status: inactive
But it's only listening on port 22
user#UBUNTUMACHINE:~$ netstat -an | grep "LISTEN "
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp6 0 0 :::22 :::* LISTEN
If I enable the firewall, and tell it to listen to 5432, it shows up in the rules:
user#UBUNTUMACHINE:~$ sudo ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip
To Action From
-- ------ ----
22 ALLOW IN Anywhere
22/tcp ALLOW IN Anywhere
5432/tcp ALLOW IN Anywhere
5432 ALLOW IN Anywhere
22 (v6) ALLOW IN Anywhere (v6)
22/tcp (v6) ALLOW IN Anywhere (v6)
5432/tcp (v6) ALLOW IN Anywhere (v6)
5432 (v6) ALLOW IN Anywhere (v6)
But I get the same results as above for netstat.
As far as I can tell from researching the issue, I have the correct values in my postgresql.conf file:
#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*' # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost'; use '*' for all
# (change requires restart)
port = 5432 # (change requires restart)
and I've tried both IP ranges and specific IPs as trusted in the pg_hba.conf file.
# Database administrative login by Unix domain socket
local all postgres ident sameuser
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all md5
# IPv4 local connections:
host all all 127.0.0.1/32 md5
# IPv6 local connections:
host all all ::1/128 md5
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local replication postgres peer
#host replication postgres 127.0.0.1/32 md5
#host replication postgres ::1/128 md5
host all all 10.0.0.0/255 trust
host all all 10.11.0.0/255 trust
host all all 0.0.0.0/0 trust
Lastly, Postgres is running, per
user#UBUNTUMACHINE:~$ sudo service postgresql status
● postgresql.service - PostgreSQL RDBMS
Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled)
Active: active (exited) since Wed 2017-03-08 11:09:57 CST; 57min ago
Process: 787 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
Main PID: 787 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/postgresql.service
Mar 08 11:09:57 UBUNTUMACHINEsystemd[1]: Starting PostgreSQL RDBMS...
Mar 08 11:09:57 UBUNTUMACHINEsystemd[1]: Started PostgreSQL RDBMS.
Mar 08 11:32:21 UBUNTUMACHINEsystemd[1]: Started PostgreSQL RDBMS.
Mar 08 11:32:26 UBUNTUMACHINEsystemd[1]: Started PostgreSQL RDBMS.
The log is telling me invalid CIDR mask in address 10.0.0.0/255
:: 255 might be larger than 32
Postgres refuses to start, because it refuses the netmask /255 which islarger than the possible number of bits in the (32 bits) IP-address. You could consider this to be a bit picky for the .hba parser, but it could also be considerered a configuration error.
In any case: replace the /255 by something sensible, like /24 (or /16, since you have two of these entries) And: replace the trust by something more safe, after it appears to work.
My logstash version is:
# /opt/logstash/bin/logstash --version
logstash 2.2.4
it is configured to receive input from port 5044 according to the filebeat file:
/etc/logstash/conf.d/02-beats-input.conf
input {
beats {
port => 5044
ssl => false
ssl_certificate => "/etc/pki/tls/certs/logstash-forwarder.crt"
ssl_key => "/etc/pki/tls/private/logstash-forwarder.key"
}
}
I have set ssl to false as I am not using it
but when I start the logstash service normally with systemctl it start and checking the status confirms it is running
systemctl status logstash
● logstash.service - LSB: Starts Logstash as a daemon.
Loaded: loaded (/etc/rc.d/init.d/logstash)
Active: active (exited) since Mon 2016-07-18 19:14:51 BST; 15h ago
Docs: man:systemd-sysv-generator(8)
Process: 19965 ExecStop=/etc/rc.d/init.d/logstash stop (code=exited, status=0/SUCCESS)
Process: 19970 ExecStart=/etc/rc.d/init.d/logstash start (code=exited, status=0/SUCCESS)
...
logstash started
The problem is that logstash does not seem to be receiving input on port 5044. hosts sending filebeats encounter:
single.go:126: INFO Connecting error publishing events (retrying): dial tcp 192.72.0.92:5044: getsockopt: connection refused
when I check the port
# netstat -an | grep 5044
I get nothing. So even though logstash is running, I can't tell what port it is bound to and listening on.
Also the firewall is stopped temporarily to investigate this.
The strange thing is that is I run logstash is debug mode like so:
# ./logstash --debug -f /etc/logstash/conf.d/02-beats-input.conf
I can see
# netstat -an | grep 5044
tcp6 0 0 :::5044 :::* LISTEN
tcp6 0 0 192.72.0.92:5044 192.168.36.70:53720 ESTABLISHED
tcp6 0 0 192.72.0.92:5044 192.72.0.90:45980 ESTABLISHED
tcp6 0 0 192.72.0.92:5044 192.72.0.90:45975 ESTABLISHED
tcp6 0 0 192.72.0.92:5044 192.72.0.90:45976 ESTABLISHED
or
# lsof -i :5044
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
java 15136 root 7u IPv6 7191510 0t0 TCP *:lxi-evntsvc (LISTEN)
java 15136 root 33u IPv6 7192379 0t0 TCP hostname:lxi-evntsvc->192.72.0.90:45975 (ESTABLISHED)
and the host sending filebeats can connect
output.go:87: DBG output worker: publish 7 events
2016/07/19 10:02:08.017890 client.go:146: DBG Try to publish 7 events to logstash with window size 10
2016/07/19 10:02:08.038579 client.go:124: DBG 7 events out of 7 events sent to logstash. Continue sending ...
2016/07/19 10:02:08.038615 single.go:135: DBG send completed
Please help point out what I may be doing wrong with this configuration. Thanks
Based on the hing provided by #LiGhTx117
I think
The startup script used by logstash in:
/etc/init.d/logstash
has the following variables among others:
LS_USER=logstash
LS_GROUP=logstash
LS_HOME=/var/lib/logstash
LS_LOG_DIR=/var/log/logstash
LS_LOG_FILE="${LS_LOG_DIR}/$name.log"
LS_CONF_DIR=/etc/logstash/conf.d
The ownership and permission on these seem to be the issue.
I ensured that the directories where recursively accessible to the
user logstash as well as the group logstash
and
Then I also ensured that the log_file: logstash.log was writeable by
the user/group logstash
restarted logstash