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--- litespeed_wiki:license:what_license_to_choose [2014/03/28 21:15]
Michael Armstrong
+++ litespeed_wiki:license:what_license_to_choose [2016/04/15 15:37]
Michael Alegre removed
@@ Line 15: / Line 15: @@
 LiteSpeed Web Server Enterprise Edition has 6 different licenses to choose from. These licenses reflect how much power LiteSpeed Web Server will be given. Generally, the licenses are divided by how many cores LSWS will have access to, though there are two special, more affordable licenses only for VPSs.
-  * VPS Licenses: An affordable option for a smaller VPS. The VPS license has a limit of 500 concurrent connections and 2GB RAM. The VPS license has access to one core on your server.
+  * VPS Licenses: An affordable option for a smaller VPS. The VPS license has a limit of [[#how_do_i_check_how_many_concurrent_connections_i_have|500 concurrent connections]] and 2GB RAM. The VPS license has access to one core on your server.
-  * Ultra VPS Licenses: A solution for VPS users who have between 2GB and 8GB of RAM. The Ultra VPS license has a limit of 800 concurrent connections. VPS users with more than 8GB of RAM will require a 1-CPU license. (The Ultra VPS license is only supported on LiteSpeed Web Server v4.2.2 and up.)
+  * Ultra VPS Licenses: A solution for VPS users who have between 2GB and 8GB of RAM. The Ultra VPS license has a limit of [[#how_do_i_check_how_many_concurrent_connections_i_have|800 concurrent connections]]. VPS users with more than 8GB of RAM will require a 1-CPU license. (The Ultra VPS license is only supported on LiteSpeed Web Server v4.2.2 and up.)
   * 1-CPU, 2-CPU, 4-CPU, and 8-CPU Licenses: All other licenses are differentiated by the number of cores they are allowed to make use of. The number of CPUs in the license title refers to the number of the server's cores that LSWS will be able to make use of. Thus a 1-CPU license has access to one core, and a 2-CPU license has access to two cores, etc. Note that **you do not need to have LSWS make use of all your server's cores.** ([[#choosing_the_right_license_for_you|See below.]]) LSWS is fast and lightweight enough to run very, very well on only a fraction of the server's cores.
   * LSCache: LiteSpeed Cache, our extremely powerful page caching feature is bundled free with 2-CPU licenses and up. For all other licenses, LSCache can be bought as a separate module.
@@ Line 22: / Line 22: @@
 **Notes:** VPS and Ultra VPS licenses will not install on a dedicated server or a VPS over their respective RAM limits. If the concurrent connection limit is surpassed, extra connections will be queued until there is room in the connection limit. Currently supported VPS platforms are KVM, HyperV, Virtuozzo, OpenVZ VPS, XEN, VMWare and UserModeLinux VPS.
-===== Choosing the Right License for You =====
+===== Choosing the Right License =====
 You do **NOT** need to buy a license to match the number of CPUs or cores on your physical server. The number of CPUs in the license title simply denotes the number of cores the LSWS process will be able to utilize. LSWS is fast and lightweight enough to run very, very well on only a fraction of the server's cores. In almost all cases, you are better off buying a license for a fraction of your server's cores and leaving the other cores for heavier processes like PHP and MySQL.
@@ Line 34: / Line 34: @@
 Often, finding exactly the right license for your usage is a matter of trial and error. Different sites put pressure on different parts of the server. The best approach may be to purchase a license, then try upgrading or downgrading to see if it affects your service noticeably. You can upgrade or downgrade at any time and you will only be charged (or credited) the difference in the license fee for the remainder of the billing period.
   *  What other processes are running on the same server?
-For example, if you have a 4-core server and run LSWS, PHP, and MySQL on the same server, you can buy 1 or 2-CPU license, as your other CPU power will be fully utilized by PHP and MySQL processes. Usually for a 4-core server, you will not need anything higher than a 2-CPU license if you have other external applications like PHP or RoR.
+For example, if you have a 4 core server and run LSWS, PHP, and MySQL on the same server, you will probably be best served by a 1- or 2-CPU license. LSWS is light enough that it only needs access to 1 or 2 of this server's cores. PHP and MySQL (which are much more resource intensive than LSWS) will be unaffected by this limit and will have access to all 4 of the server's cores.
-  *  Do you have a high volume of HTTPS traffic?
-This requires more CPU power for encryption.
   *  Is the content you serve mainly static (such as images, file downloads, etc.)?
-These are served by LSWS directly, so more CPU will help. If your server is mainly PHP/MySQL powered, a 4-CPU license may not help much as LiteSpeed will not be the bottleneck.
+Static content is served by LSWS directly, so more CPUs may help. If your server is mainly using PHP or MySQL (for instance, if it is running web applications like WordPress, etc.), giving LSWS access to more cores will not help as LSWS is not the bottleneck.
-  *  What is 'disk I/O wait?'
+  *  Do you have a high volume of HTTPS traffic?
-Like all other lightweight web servers, blocking disk I/O will block LiteSpeed's process. Therefore, if your server has high I/O wait, you should consider a higher CPU license in order to compensate. Since version 4.1, LiteSpeed has supported AIO (asynchronous IO).
+HTTPS requires more CPU power for encryption. You may find that giving LSWS access to more cores in this case improves performance. Do not overestimate this effect, though. Unless your server only serves static HTTPS, LSWS should still only have access to a fraction of the server's cores.
-  *  VPS licenses cost less, but have restrictions of 500 concurrent connections and a 2GB memory limit.
-  *  Ultra VPS, with restriction of 600 concurrent connections and an 8GB memory limit, has been available since March 2013.
-===== How do I check concurrent connections for my server? =====
+==== Indicators that you might need to upgrade your license ====
-There is limit for max concurrent connections for different licenses. The free version has a limit of 150, the VPS license, 500, Ultra VPS, 600, and the Enterprise edition is unlimited.
+A ''top'' command will reveal important information about how many resources different processes are taking on your server. (LSWS's process is called ''lshttpd''.) A couple of these outputs are useful for determining if your installation of LSWS needs access to more cores:
-You can check the number of concurrent connections used from the real-time report under web admin console, or use the command <code>netstat -an | grep 80 | grep ESTA | wc -l </code> Remember, though, only “established” connections from netstat output are considered to be concurrent. For example, a forum with 3,000 users online might only use 300 concurrent connections, as those 3,000 users do not all execute actions at the exact same split second.
+  * %CPU - Generally LSWS's CPU usage is low. If LSWS's CPU usage starts climbing and especially if it climbs while your overall load is low, that can indicate that LSWS is hitting a bottleneck and would benefit from access to more cores.
+  * %wa - High I/O wait can also be an indicator that LSWS needs more worker processes (and thus access to more cores).
+=== How do I check how many concurrent connections I have? ===
+Some editions and licenses have a limit on the maximum number of concurrent connections you can serve. Our Standard Edition has a limit of 150 concurrent connections. The VPS license has a limit of 500, and Ultra VPS has a limit of 800.
+If you've already installed LSWS, you can check the number of concurrent connections in the Real-Time Statistics report in the WebAdmin console.
+Even without LSWS you can use the command <code>netstat -an | grep 80 | grep ESTA | wc -l </code> to check the number of concurrent connections. The number returned by this command is your current number of concurrent connections. You may be surprised how few concurrent connections you have. (For example, a forum with 3,000 users online might use 300 concurrent connections or less, as those 3,000 users do not all execute actions at the exact same split second.)