Service configuring linux server by each method

linux server configuration service

Linux virtual server (LVS) is a technique of grouping single servers into a single server without the user knowing about the existence of these individual servers. This single server is called a virtual server or a load balancer – the load balancer has a virtual IP address (Virtual IP or VIP) and behind it are the real servers.

Linux virtual server handling methods linux server configuration service

LVS has 3 methods to handle requests sent from users, which are:

LVS VIA NAT

LVS VIA IP tunneling

LVS VIA Direct Routing

1. What is LVS VIA NAT? linux server configuration service

Linux Virtual Server via NAT the simplest technique. Real servers just need to be any operating system that supports the TCP/IP stack. LVS NAT uses IP masquerading technique in Linux. Load balancer Load Balancer will receive requests from users via virtual IP which is a public IP, then this load balancer will transfer packets to real servers through private IPs and finally pass responses back to users. .

Let's see a star example to better understand LVS NAT. Suppose we have:

Client Source Address: 183.83.214.214

Virtual IP (IP assigned to Load Balancer): 212.71.233.103

Real Server1: 10.1.10.1

Real Server2: 10.1.10.2

Step 1: User(183.83.214,214) sends request to VIP of Load balancer(212.71.233.103)

Step 2: Receiving the request, the Load balancer checks the destination address and port and will save the connection information in a table, then pass it to a selected real server in the pool by the selection algorithm. Now the connection of the request looks like this:

Step 3: Load balancer receives the response from the real server and rewrites the source address of the packet and returns it to the user:

The advantage of LVS NAT is that the real server can run any operating system and only needs one IP address in front of the Load balance.

2. What is LVS VIA IP Tunneling?

LVS IP Tunneling is a better solution than LVS NAT for 2 reasons:

First, the load balancer does not have to repeatedly record the address of the packet

Second, the returned response does not need to go through the Load Balancer.

The steps are described as follows:

Step 1: Client sends request to VIP, here is the address of Load Balancer

Step 2: Load Balancer checks the packet with the service in it, it encapsulates the packet inside another IP packet and forwards it to the Real Server. The Load Balancer will add connection information to the routing table so that subsequent requests coming from the same connection can be forwarded to the same Real server that is processing the old request.

Step 3: Real Server peels the packets sent by the Load Balancer, reads the original packet from the client and processes the data and returns it directly to the client. linux server configuration service

The advantage of this method is that the Load Balancer will not be overloaded with changing packets, but the disadvantage is that it requires the Real server to support IP Tunneling.

3. What is LVS VIA Direct Routing?

In this method, we no longer have to worry about tunneling like LVS Tunneling or rewrite packets of LVS NAT. This method is quite similar to the second method in that the Response will be returned directly from the real server to the user.

Virtual IPs are assigned and shared both on the Load Balancer as well as on the real servers. The important point in this method is that because the Load Balancer and the real server are on the same physical network, the virtual IP must be assigned to the interfaces that do not respond to ARP requests - non-arp interfaces.

Step 1: As usual, the client sends a request to the VIP on the Load Balancer. LB will forward it to the real servers according to the algorithm of choice. When the real server receives the request, it will change the frame of the packet with the mac address of the real server to retransmit on the LAN. That's why the LB and the real server must be on the same LAN segment.

Step 2: The real server has the same virtual IP configured on the non-arp interfaces, it receives the packet and processes it, then passes the response back to the client.linux server configuration service

The main advantage of this method is to reduce the load at the nodes, but the disadvantage is that it requires the Real Servers and Load Balancers to be on the same network segment.

Advantages and uses of Linux Server linux server configuration service

1. Advantages

The dominance of Windows and Mac OS did not stop operating systems from evolving. Open source operating systems like Linux are still going strong. In addition to the usual functions, Linux also possesses many other outstanding advantages. Such as:

No cost to buy/sell license: With this operating system, you don't need to pay for a license fee and can use all the features. Includes OpenOffice and LibreOffice office applications.

High security: All malicious software such as viruses, malicious codes ... cannot work on Linux. Therefore, the security of the operating system is very high.

Flexibility: In particular, users can also edit the operating system according to their needs. This is the ideal opportunity for programmers as well as developers.

Works "smoothly" on computers with weak configurations: With Linux, when upgrading to a new version, computers with weak configurations will still be regularly upgraded and supported - ie the quality of operation is still smooth. tru and stable.

2. What is the use of Linux?

Linux is a major threat to the Windows and Mac OS markets. Why? Linux possesses many outstanding features, such as:

Manage and coordinate system resources.

Make it possible for users to see almost every line of code in Linux. The best support for operating system editing and development based on the unique needs of customers.

All features are free and no license required.

Diverse interface, high security, regularly upgraded to new versions.

In particular, the Linux operating system is relatively light. Therefore, machines with weak configuration can still operate stably on this operating system.

Why choose Linux Server?

1. Linux virtual server with high stability

Linux impresses when it can run for years without problems. Small and medium businesses can rest assured when using a Linux virtual server because of its stability, limiting the risks of server failure. linux server configuration service

Linux servers can handle a large volume of tasks occurring at the same time better than Windows servers. Linux servers often limit degradation, do not lose stability when having to handle many tasks at the same time.

For Linux there is no downtime because all Linux configuration changes can be made while the system is up and running without affecting other unrelated services.

2. High security

Linux is built on top of Unix - a multi-user operating system. Only the administrator or root user has full control over the system and also some users can be granted access to use important tasks. This gives the Linux server maximum protection.

3. Flexibility

Linux is very flexible and extensible, it can work well on any computer, regardless of the processor and architecture of the machine.

Linux servers can also be easily reconfigured for business-specific purposes, reducing memory requirements and enhancing machine performance. .

4. Low cost

Linux is almost free software, so in terms of price, it is difficult for any competitor to surpass Linux.

5. Be more active in using linux server configuration service

Using a Linux server, you are free to mix and match and choose what you feel is right for your business without the hassle of licensing or paying for any services. .