The number of authenticated “handshakes” between a client and/or server during any given time. Before all communications have been disconnected whether by force or by refusal. In layman’s terms: “how many people are using your website or calling a task at one time.”
Scenario of Concurrent Connection:
e.g. if visitors click to read a thread in your forum, then a post in that thread, that is 2 connections, but they are one at a time.
or another scenario;
If you have 10 people who click to read any post at the same time, (not the same post), that is 10 concurrent connections. As each one finishes, and the page is loaded, that connection is closed.
About Concurrent Connection
When accessing your website’s capabilities and resources, two important terms you may want to become familiar with. They are “concurrent connection” and “visitor.” By definition they are the following:
- Concurrent Connection: The maximum amount of simultaneous connections your server can handle.
- Visitors: Someone who goes to your website.
When a visitor goes into a browser and tries to load your site, they become a concurrent connection. This occurs because a connection is required for the server to send your website data over to the visitor. Once the page finishes loading, it drops the connection. The visitor can continue to view your webpage. Besides, during this time, they are not taking up a slot. However, once the visitor decides to clicks on a link, play a video, or some other activity that requires a connection, they will then become a concurrent connection again.
So what does this mean?
This means that you can generally have a large number of visitors viewing your website (much larger than your concurrent connection capacity), as long as they don’t all make connections at the same time.
Here's a "real world" example that might help illustrate this relationship:
Let’s suppose you invite some friends over to play a board game.
The board game has a limit of how many people can be actively playing the game at one time (this is your concurrent connections). But, you can have plenty more people who can passively watch the game (these are your visitors).
When a person is done playing the game, they stand up and can begin watching the game passively. This frees up space so now a new person can sit down and actively play the game.
This overall illustrates how the maximum number of concurrent connections differs from your visitor limitation. However, when your site is optimally built, they are typically fast and efficient. So the exchange of active connections and passive visitors is constantly changing.
Are there any problems that can occur with concurrent connections?
Outdated CMS, plugins, themes, or non-optimized code can result in longer times. This could also result in connections not being dropped after a visitor is finished. This can essentially trick your server into thinking someone is trying to make a concurrent connection. However, in reality, it should have been dropped.
Each Media Temple server type has a different concurrent connection capacity. You could anticipate a large number of these connections to your website. To do this, you may want to consider adding a Grid Container or moving to a VPS server. This is to increase the capacity of your concurrent connection. If you’d like to view your server’s concurrent connection capacity or wish to see the different options for increasing your capacity.