ansible notify

Background information:There are a lot of facts in ansible, but not enough in many cases.For example, Ansible has no ansible_private_ipv4_address such a facts, which is used to save a private network IP address.And we just need such a facts, because we have a lot of server's default network card is not eth0, some bond0,eth1,em0,em1, and the public network IP address and private network IP address also does

Handlers action to take when a change occursmodule has idempotent, so when the remote system is changed, you can replay playbooks to achieve recoveryObjective. The playbooks itself can identify this change, and there is a basic event system that canRespond to this changeNotify actions are triggered at the end of each task in playbook, and even if there are many differentTask notification changes occur, notify actions will only be triggered onceFor exa

Having read a book about concurrency, there is a conclusion that using Notifyall is a safer procedure. Take the message queue as an example, assuming that the action put into the element is put, taking the action of the element as the last sentence of Take,put may be if (count = = 1) {Notempty_cond.notify_all ();} If you change the Notify_all to notify (), there are cases where concurrency is not sufficient: assuming that the queue is empty for severa

one, Wait (), notify (), Notifyall () 1, signal volume One of the easiest ways to communicate between threads is to set the semaphore in a variable of a shared object. Thread A sets the Boolean member variable hasdatatoprocess to true in a synchronized block, and thread B reads hasdatatoprocess This member variable in the synchronization block. The following example uses a signal-holding object and provides set and check methods: public class mysign

Ansible-playbook Reference(1) Basic example~]# vim base.yaml-hosts:192.168.1.114 remote_user:root tasks:-name:install httpd server yum:name=httpd state= Present-name:start httpd Server service:name=httpd state=started(2) Handlers example~]# vim handlers.yaml-hosts:192.168.1.114 remote_user:root task:-Name:install httpd yum:name=httpd state=pres Ent-name:install Configure file copy:src=file/httpd.conf dest=/etc/httpd/conf/httpd.conf

Wait (), notify (), Notifyall () are not part of the thread class, but belong to the object base class, which means that each pair has wait (), notify (), Notifyall ()function. Because all have a lock on the image, the lock is the basis of each pair of image, of course, the method of operation lock is the most basic.wait and notify are an important part of the Ja

In Java, you can use the Wait () method and the Notify () method or the Notifyall () method to invoke the object objects to enable communication between threads. Calling the Wait () method in the thread will block notifications waiting for other threads (other threads call the Notify () method or the Notifyall () method), call the Notify () method or the Notifyal

In Java, you can use the Wait () method and the Notify () method or the Notifyall () method to invoke the object objects to enable communication between threads. Calling the Wait () method in the thread will block notifications waiting for other threads (other threads call the Notify () method or the Notifyall () method), call the Notify () method or the Notifyal

Tag: Hose ack Time decides to synchronize trace information about comparisonOriginal link Java concurrent programming: two ways to collaborate between threads: Wait, notify, notifyall, and conditionIn the front we will have a lot of questions about synchronization, but in reality, there is a need for collaboration between threads. For example, the most classic producer-consumer model: When the queue is full, the producer needs to wait for the queue to

After reading the basis of ansible, and then wrote three simple deployment of YML, respectively, installation Nginx, MySQL, tomcat+jdkPut the source code here, has been tested to pass theTomcat:/etc/ansible/roles/tomcat/├──defaults│└──main.yml├──files│├──apache-tomcat-7.0.52.tar.gz│├──apr-1.5.1.tar.bz 2│├──apr-util-1.5.4.tar.bz2│├──jdk-7u55-linux-x64.tar.gz│└──profile├──handlers│└──main.yml├──meta│└── Main.