SAP HANA SQLScript Reference, and used to program SQL Script is a script language, documented in the METHOD - BY DATABASE PROCEDURE, FUNCTION →ĪMDP - SQL Script for the SAP HANA Database ABAP - Keyword Documentation →ĪMDP - ABAP Managed Database Procedures → I guess I am like a proud papa describing my daughter’s school performance.SAP NetWeaver AS ABAP Release 752, ©Copyright 2017 SAP AG. Sorry for the long winded explanation, but we have spent many hundreds of engineer hours analyzing performance & resilience metrics and refining our ideal scalable cluster. In all of our testing, there is no noticeable slowdown, and it enables us to do many things that improve the responsiveness, robustness, and metrics of the overall system. So yes, I like sessions being stored in database. If the Web servers were storing the session data in a local file instead of the database, then the session would be lost when the web server died and the user would have to log in again and begin a new session on the other web server. Because of storing the session data in database, if you are on web server A and it dies suddenly, your next page access will come from web server B and the user will never even know it. As a matter of fact, I can have either web server die at the same time as either sql server, and the web site is still up - this is called “High Availability”. I can add more servers whenever I like, and either one can die without affecting anything else. Again, the load is balanced to direct queries to the least busy server. Likewise, I have two web servers, both running identical production copies. Takes minutes, not hours to bring a new one online. I can add more MySQL servers as I may need to, very easily (even in geographically different places). I run a HA-Proxy front end that balances the load between the two sql servers. Also, either one can die without anything being adversely affected. They are configured for master-master replication so you can access either one and get exactly the same data. As a result, MySQL runs on 2 dedicated servers. If our users go from 2,000 to 20,000 unexpectedly, we need to be able to scale quickly and easily. In my environment, it is very important to us to have a scalable server farm. This is the same as the timeout that you sometimes experience in ScriptCase Development Mode. They have no idea that you have closed your browser. So, if you close your browser without logging out, the session will disappear off the server 15 minutes after the last session variable was written to. scriptcase global variable) gets modified. But the timeout, say 15 minutes, gets reset every time a session variable (i.e. You also can manipulate the session via PHP functions - kill a session, start a new session, etc. That is defined as ‘some configurable period’ without any writes to a session variable. In terms of how long the data lives in the database, the data is deleted upon expiration of the session. Between servers I have a 100MBit ethernet backchannel, and you absolutely cannot notice any difference in speed, session in database or session in files. So next question would be “how about if the SQL server is on a different machine than the web server”. How much more overhead can there possibly be if, instead of a file managed by Apache/PHP, the data is stored in a database managed by MySQL? If Apache/PHP and MySQL are running on the same server, many people say that MySQL access of session data is faster than Apache/PHP’s. The file lives until session expiration at which time the session file is deleted. When you update a session variable (write to a ScriptCase global variable) the file is updated. When you access them, they are read into memory. If you think about it, the way that session variables are normally kept on a web server, they are stored in a session file.
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