Recently I found that the memory of the blog was always being "eaten" every now and then. After logging in to the backend, there would occasionally be lags. At first, I suspected that it was caused by insufficient Swap, so I added a few G of Swap to the VPS host and observed. After a while, I found that no matter how big the Swap was, it was slowly "eaten"!
The website is located abroad, so I have been thinking about how to maximize the speed of opening the web page. I used Alibaba Cloud Hong Kong VPS host before, and the speed was quite fast. However, students often reported to me that they could not open it, or they could not access it one after another. After investigation, it was determined that the problem was in the SSL handshake stage, so I switched to CN2 GIA VPS.
If you are with a hosting provider that uses WHMCS+VPS management platform architecture like Classic VPS, then you need to upgrade the entire VPS hosting package yourself to expand the hard drive. However, if you purchase a VPS host from a cloud host provider such as Linode, Alibaba Cloud, Tencent Cloud, etc., then when the hard drive is full, it supports independent expansion of the hard drive.
Independent servers can be bound to multiple IPs, and merchants generally give away 2-5 IP addresses when purchasing independent servers. Independent IP addresses are very beneficial to SEO for multiple sites. Of course, it is a waste to use a dedicated server to build a website. We can virtualize the dedicated server into a VPS host so that more people can use it.
In the process of using WordPress to build a website, many "detours" have been taken in optimizing WordPress performance and speeding up website access. When the website access is slow and the CPU memory is exhausted, the first thing I think of is upgrading the server configuration. Later, I find that some unscrupulous VPS merchants severely restrict resources behind the scenes, and it is really hurtful to pay more to upgrade.
There are many friends who have built foreign trade websites who want to restrict their websites from being accessed by domestic IPs. There are also some friends whose websites store resources that need to be blocked from specific IPs for various reasons. Some friends have seen attacks. Most of the source IPs come from abroad, and you want to prevent foreign IPs from accessing the website.
Regarding the problem of the Linux disk being full, I have encountered it before when using the WDCP panel because the website log was enabled in the background of the panel, but the log was not deleted regularly. In the long run, the disk space of the VPS host was filled up with logs. When the disk space reaches 100%, some inexplicable errors will occur on the website, such as being unable to log in to the background, unable to comment, and the page is blank, etc.
Recently, when a friend was using his Yunfu host, he discovered that SSH has been violently scanned by others. Although the SSH account and password have never been guessed, if someone keeps staring at him, something will happen sooner or later. I helped him set up an S-S-H login whitelist, which only allows login access from his own IP, and rejects all other IPs.
As everyone's awareness of online security increases, and major Internet companies promote the popularization of HTTPS, HTTPS SSL has now basically become the standard for building websites. Thanks to the free SSL certificates provided by Let’s Encrypt, Digicert, TrustAsia, Symantec, etc., the cost of using HTTPS is now negligible whether it is a personal website or a corporate website.
Due to the increase in the number of CN2 space users, Mysql process has always crashed in the middle of the night recently. I checked the Mysql error log and the prompts are: [ERROR] Error in accept: Too many open files. It turns out that it is because of open files. Insufficiency causes the database to hang up, especially when the DirectAdmin system is backed up at night.
