Apache failover setup

It facilitates communication between the Apache web server and Tomcat server nodes using AJPv13 protocol. AJPv13 protocol is available in Tomcat 4 and above. Execute the following command to open the server. Configured load factor for node2 worker. Disable node2 for all requests except failover worker. In all other cases node2 will not receive any requests, thus acting like a hot standby.

Once the setup is complete, any request which will be sent to the load balancer IP will be redirected to one of the nodes based on configured load distribution policy like sticky sessions, load factor lbfactor or failover mechanism.

You are commenting using your WordPress. You are commenting using your Google account. Licensed under the Apache License, Version 2. Reverse Proxy Guide Available Languages: en. Simple reverse proxying The ProxyPass directive specifies the mapping of incoming requests to the backend server or a cluster of servers known as a Balancer group. Clusters and Balancers As useful as the above is, it still has the deficiencies that should the single backend node go down, or become heavily loaded, that proxying those requests provides no real advantage.

Hint BalancerMembers are also sometimes referred to as workers. Balancer and BalancerMember configuration You can adjust numerous configuration details of the balancers and the workers via the various parameters defined in ProxyPass.

Failover You can also fine-tune various failover scenarios, detailing which workers and even which balancers should accessed in such cases. Balancer Manager One of the most unique and useful features of Apache httpd's reverse proxy is the embedded balancer-manager application. Dynamic Health Checks Before httpd proxies a request to a worker, it can "test" if that worker is available via setting the ping parameter for that worker using ProxyPass.

The meanings of these statuses are as follows: Flag String Description Ok Worker is available Init Worker has been initialized D Dis Worker is disabled and will not accept any requests; will be automatically retried.

S Stop Worker is administratively stopped; will not accept requests and will not be automatically retried I Ign Worker is in ignore-errors mode and will always be considered available. We have integrated SafeKit in our critical projects like the supervision of Paris metro Line 4 the control room or Marseille Line 1 and Line 2 the operations center. Thanks to the simplicity of the product, we gained time for the integration and validation of the solution and we had also quick answers to our questions with a responsive Evidian team.

The software integrator Systel deploys SafeKit high-availability solution in firefighter and emergency medical call centers. Its main advantage is that it brings in high availability through a software option that is added to our own multi-platform software suite. This way, we are not dependent on a specific and costly hardware clustering solution that is not only difficult to install and maintain, but also differs according to client environments.

With SafeKit, our firefighter call centers are run with an integrated software clustering solution, which is the same for all our customers, is user friendly and for which we master the installation up to after-sales support. Our critical activity is thus secure, with high-availability and load balancing functions. The advantages of this product are easy deployment and administration of clusters, on the one hand, and uniformity of the solution in the face of heterogeneous operating systems, on the other hand.

The solution does not require load balancers or dedicated proxy servers above the farm for imlementing load balancing. SafeKit is installed directly on the Apache servers in the farm. This is not the case with dedicated proxies on Linux. This is not the case with a specific multicast Ethernet address on Windows.

This is not the case with other load balancing solutions. They are able to make load balancing but they do not include a full clustering solution with restart scripts and automatic Apache restart in case of failure.

They do not offer a replication option. There is no domain controller or active directory to configure on Windows. The solution works on Windows and Linux. If servers are connected to the same IP network through an extended LAN between remote sites, the virtual IP address of SafeKit is working with load balancing at level 2. If servers are connected to different IP networks between remote sites, the virtual IP address can be configured at the level of a load balancer with the help of the SafeKit health check.

Thus you can implement load balancing but also all the clustering features of SafeKit, in particular monitoring and automatic recovery of the critical application on application servers. SafeKit imlements a farm cluster with load balancing and failover. But it implements also a mirror cluster with replication and failover. Thus a N-tiers architecture can be made highly available and load balanced with the same solution on Windows and Linux same installation, configuration, administration with the SafeKit console or with the command line interface.

This is unique on the market. This is not the case with an architecture mixing different technologies for load balancing, replication and failover. A simple software cluster with the SafeKit package just installed on two servers. Complex hardware clustering with external storage or network load balancers. SafeKit is a shared-nothing cluster: easy to deploy even in remote sites. A shared disk cluster is complex to deploy. Application HA supports hardware failure and software failure with a quick recovery time RTO around 1 mn or less.

Application HA requires to define restart scripts per application and folders to replicate SafeKit application modules. Full virtual machines HA supports only hardware failure with a VM reboot and a recovery time depending on the OS reboot.

No restart scripts to define with full virtual machines HA SafeKit hyperv. No dedicated server with SafeKit. Each server can be the failover server of the other one. Software failure with restart in another OS environment. Secondary server dedicated to the execution of the same application synchronized at the instruction level.

Software exception on both servers at the same time. Smooth upgrade not possible. SafeKit implements real-time synchronous replication with no data loss in case of failure. With asynchronous replication, there is data loss on failure. SafeKit implements real-time byte-level file replication and is simply configured with application directories to replicate even in the system disk. Server Fault is a question and answer site for system and network administrators. It only takes a minute to sign up.

Connect and share knowledge within a single location that is structured and easy to search. How can I have the second connection take over when the primary one fails? I have seen that it is possible to have two A records, each pointing to a different IP, but it has several problems. What's the real solution to this?

I imagine this is a very common issue. The server is actually an electronic medical record server, and has to be on-site at the office. Their website and DNS is hosted at a large managed hosting facility. I think the plan on the office side is something like the Peplink Balance previously mentioned or Cradlepoint MBR I will look further into this for sure. After talking to our hosting facility, they recommended we look into a third party service like Dynamic DNS.

I believe it's basically a monitoring service which switches when one IP goes down. Actually no. Most even smaller websites run with hosters who handle that.

The hoster has multiple uplinks, his own address space and announces his routing via BGP to the peers. This is also a lot more bandwidth efficient as basically This would be with more of a 'real' connection that cable and dsl. For those levels of connections I think using DNS failover is probably on par with your setup.

I normal next stage would be to move to collocation and get a stable connection from an ISP offered at the collocation facility or the datacenter itself. They can give you two drops that use HSRP probably and they can go right into a switch or switches.