Архів теґу: system

TCP state diagram

Ansible. nmcli module. Failed to import the required Python library

In new version of Ubuntu/Centos need to use new name of imported module. When using old nmcli.py i had this error: Failed to import the required Python library (NetworkManager glib API) on node’s Python /usr/bin/python3. Please read module documentation and install in the appropriate location. If the required library is installed, but Ansible is using… Читати далі »

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… Читати далі »

QRencode

Забавна программа якщо треба перенести якийсь текст на телефон, а під рукою нема ніяких штатних месенджерів echo “text_string” | qrencode -t UTF8 -o – █████████████████████████████ █████████████████████████████ ████ ▄▄▄▄▄ █▀▄█▀▄█ ▄▄▄▄▄ ████ ████ █ █ █▀▄█▀██ █ █ ████ ████ █▄▄▄█ █▀▀ ▄ █ █▄▄▄█ ████ ████▄▄▄▄▄▄▄█▄█ ▀ █▄▄▄▄▄▄▄████ ████ ▄▄▄ ▀▄▄ ██ ▄█▄▀ ▀▄▀████ █████▀▄▄▄█▄█▀█▀▄█▀▄▀█… Читати далі »

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-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… Читати далі »

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.