Zookeeper RPM for Centos 7
prepared rpm package for zookeper
Centos 8 – update linux kernel
rpm –import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org dnf install https://www.elrepo.org/elrepo-release-8.0-2.el8.elrepo.noarch.rpm So, install the new kernel. :~# dnf –enablerepo=elrepo-kernel install kernel-ml Setup new Kernel to default grub2-set-default 0 grub2-mkconfig -o /boot/grub2/grub.cfg
Mikrotik as OpenVPN server in 3 steps
Connect to Mikrotik via SSH and start writing text below Set global VARs Make server and client CRT Create pool, profile, interface, firewall Goto menu Files in Mikrotik admin panel and download ca.crt + client.crt + client.key Then make file SomeName.ovpn with content: Put your key and crt and change host:port vars and file auth.cfg with this two files you can start client
Configure Apache for A-rating on SSLLabs
Just add following lines to vhost.conf SSLEngine on SSLProtocol TLSv1.2 TLSv1.1 SSLProxyProtocol TLSv1.2 TLSv1.1 SSLHonorCipherOrder on SSLCipherSuite EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:ECDHE-RSA-AES128-SHA:DHE-RSA-AES128-GCM-SHA256:AES256+EDH:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA25
Flume: java.lang.NoClassDefFoundError: org/apache/hadoop/io/SequenceFile$CompressionType
error: 2017-08-09 12:29:09,754 (conf-file-poller-0) [ERROR – org.apache.flume.node.PollingPropertiesFileConfigurationProvider$FileWatcherRunnable.run(PollingPropertiesFileConfigurationProvider.java:146)] Failed to start agent because dependencies were not found in classpath. Error follows. java.lang.NoClassDefFoundError: org/apache/hadoop/io/SequenceFile$CompressionType at org.apache.flume.sink.hdfs.HDFSEventSink.configure(HDFSEventSink.java:235) at org.apache.flume.conf.Configurables.configure(Configurables.java:41) at org.apache.flume.node.AbstractConfigurationProvider.loadSinks(AbstractConfigurationProvider.java:411) at org.apache.flume.node.AbstractConfigurationProvider.getConfiguration(AbstractConfigurationProvider.java:102) at org.apache.flume.node.PollingPropertiesFileConfigurationProvider$FileWatcherRunnable.run(PollingPropertiesFileConfigurationProvider.java:141) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.io.SequenceFile$CompressionType at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) … 12 more2017-08-09 12:29:09,754 (conf-file-poller-0) [ERROR – org.apache.flume.node.PollingPropertiesFileConfigurationProvider$FileWatcherRunnable.run(PollingPropertiesFileConfigurationProvider.java:146)] Failed to start agent because dependencies were not found in classpath. Error follows. java.lang.NoClassDefFoundError:…
QRencode
Забавна программа якщо треба перенести якийсь текст на телефон, а під рукою нема ніяких штатних месенджерів echo "text_string" | qrencode -t UTF8 -o – █████████████████████████████ █████████████████████████████ ████ ▄▄▄▄▄ █▀▄█▀▄█ ▄▄▄▄▄ ████ ████ █ █ █▀▄█▀██ █ █ ████ ████ █▄▄▄█ █▀▀ ▄ █ █▄▄▄█ ████ ████▄▄▄▄▄▄▄█▄█ ▀ █▄▄▄▄▄▄▄████ ████ ▄▄▄ ▀▄▄ ██ ▄█▄▀ ▀▄▀████ █████▀▄▄▄█▄█▀█▀▄█▀▄▀█ ▄█████ ████▄▄▄▄█▄▄▄ ▀▄▄▀█ █▀▄█ ▀████ ████ ▄▄▄▄▄ █▄ ▄█▄ ██▀▀ ▄█████ ████ █ █ █ ▄ █▀▀ ▄▀ ▀▄▄████ ████ █▄▄▄█ █ ▄▀▀▄▀▄█▀▀ ██████ ████▄▄▄▄▄▄▄█▄▄█▄▄█▄█▄▄▄▄█████…
SSH client stuck on connect
This is probably an issue with D-Bus and systemd. If the dbus service is restarted for some reason, you will also need to restart systemd-logind restart systemd-logind service: systemctl restart systemd-logindsystemctl restart systemd-logind I had this same issue on CentOS 7, because the messagebus was restarted (which is how the D-Bus service is called on CentOS).
Linux bridge: MAC addresses and dynamic ports
Scenario: KVM virtualization host running several bridged guests. The host has a bridge interface br0 that starts out containing only eth0, and other interfaces are dynamically added and removed from the bridge as guests are started and stopped. The problem is, the host seems to randomly suffer some loss of connectivity (from a few to 30-40 seconds) when some guest is started or stopped. Initially one might think of something related to STP, but it turns out that it is…
Mysql: wrong slave_master_info after upgrade to 5.7
After upgrade mysql-server from 5.6 to 5.7.10 something strange going on with multimaster replication. When you add more then one channel replication tool not see second channel and server hangs on first channel. This happens because mysql_upgrade tool have a bug. This bug create columns in table slave_master_info in wrong order.
Apache Helix presentation
Video on youtube Docs: http://helix.apache.org/0.7.1-docs/Tutorial.html Zookeeper: http://zookeeper.apache.org/doc/r3.3.3/zookeeperStarted.html
Add CA certifice from Let’s Encrypt to Java 8
For add cert to Java 8 you need use keytool cd /tmp/ && \ curl -O https://letsencrypt.org/certs/letsencryptauthorityx1.der && \ sudo $JAVA_HOME/bin/keytool -noprompt -importcert -alias letsencryptauthorityx1 -keystore $JAVA_HOME/jre/lib/security/cacerts -file letsencryptauthorityx1.der -storepass changeit && \ curl -O https://letsencrypt.org/certs/lets-encrypt-x3-cross-signed.der && \ sudo $JAVA_HOME/bin/keytool -noprompt -importcert -alias lets-encrypt-x3-cross-signed -keystore $JAVA_HOME/jre/lib/security/cacerts -file lets-encrypt-x3-cross-signed.der -storepass changeitcd /tmp/ && \ curl -O https://letsencrypt.org/certs/letsencryptauthorityx1.der && \ sudo $JAVA_HOME/bin/keytool -noprompt -importcert -alias letsencryptauthorityx1 -keystore $JAVA_HOME/jre/lib/security/cacerts -file letsencryptauthorityx1.der -storepass changeit && \ curl -O https://letsencrypt.org/certs/lets-encrypt-x3-cross-signed.der && \ sudo $JAVA_HOME/bin/keytool -noprompt…