Hi I was thinking of setting around 40-50 or even more MySQL Event that run on an hourly basis to update a specific column data. Is it gonna cause application failure if i do so ?
The main purpose is to implement an hourly billing system by updating the column data with a fixed rate hourly
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We've got some data driven subscriptions running on SSRS.
Sometimes they take an unusually long time to complete, if I check the activity on the server I find that things are relatively quite.
What I did notice is that in the ReportServer database on the Notification table there's a column called ProcessAfter.
Sometimes this value is set about 15 minutes into the future, and the subscription only completes after the time stated in that column.
What is setting this value? Since this behaviour is relatively rare.
After a few days I posted this question here, and got an answer:
When a subscription runs, there are several things happen: The SQL
Server Agent job fires and puts a row in the Event table in the RS
catalog with the settings necessary to process the subscription. The
RS server service has a limited number of threads (2 per CPU) that
poll the Event table every few seconds looking for subscriptions to
process. When it finds an event, it puts a row in the Notifications
table and starts processing the subscription.
The only reason that rows would stay in the Notification table is that
the RS service event processing threads are not processing the events.
As per my understanding, the NotificationEntered column stores the
time when the notification enters. Delivery extension provide some
settings for specifies the number of times a report server will retry
a delivery if the first attempt does not succeed (MaxRetries property)
and specifies the interval of time (in seconds) between each retry
attempt (SecondsBeforeRetry property). The default value for
SecondsBeforeRetry is 900 seconds, means 15 minutes. When the delivery
fails, it retry attempts every 15 minutes.
Reference: Monitoring and Troubleshooting Subscriptions Delivery
Extension(s) General configuration
If there are any other questions, please feel free to let me know.
Thanks, Katherine Xiong
I found the Extension(s) General Configuration link especially helpful
I want to create a monitoring script that will check my servers. Right now I'm stuck on a problem, I need to find out a way to get uptime percentage. Basically all data is stored in MySQL server, for me the easiest way to get uptime is to create a function that will add a new record to mysql server every minute with date, time, information is it online etc. but if I will use this method and I will have for example 1000 servers to monitor, I will end up with 518 400 000 records in MySQL server per year.
Another idea was to create one record per server with two rows online and offline, but without any date and time I'm not able to get uptime...
Any ideas how to design database for monitoring system ?
The MySQL information_schema contains uptime information (expressed in seconds) for each server. I am not sure how accurate your figure has to be, but you could get this value at a set interval and compare it to the previous value. Depending on the interval, this could give you a good approximation.
SELECT Variable_Value FROM SESSION_STATUS S WHERE Variable_Name = 'UPTIME';
Also, the MySQL error log contains a date and time stamp when the server starts. Scrape this info periodically and add to your server table.
Currently i am using cron for this. I thought perhaps it is possible to implement some procedure that will remove all data from database that is older than one month, but i am not sure that this is the best way.
Problem is that we have many servers with many cron processes, that are controlled by very small amount of stuff, and we need to make it clear and easy-to-manage, that's why i don't want to have such cron process.
Data in table i want to delete - statistics, huge amount of this data is inserted every day, and if it will not be deleted - database will be unbeliaveable huge (about ~500M every day, for us it's quite big amount, 500M * 365 days is 182,5G per year)
Is it possible to delete data using some procedure in mysql (perhaps after new row is added) / and is that a good idea?
If you're intending on moving away from cron jobs, you could always create an event that runs at a scheduled frequency.
Whatever you do, it's a very bad idea to delete data every time a new row is added, as it'll slow down your insert and it's more likely to fragment your tables.
I have a resource table for a game I'm trying to code, and each resource has a fixed income rate over time. But I can't find any description on how to increase the stored values of the MySQL Table over time automatically.
I'm using NetBeans to connect the program with the database, but I want the values to be updated on the server without the need to run the program. Otherwise I would just have had the time recorded and just add the time difference value.
Is there a way of doing this?
Table:
Player ID: 1
Gold: 100
Wood: 100
Increase rate: 50 per hour
One way of doing this is using Cron jobs and schedule some script to run.
Otherwise you can simply calculate the time elapsed from the beginning and (whithout updating your DB) calculate values based on the time when your program is running.
You can define a cron job on the server, that runs a query to update the values.
Yes, you can by adding a scheduled event like this. However, if you update the value in the database, the value/variable stored by the program will not be updated in real-time: you have to query the database for the updated value.
Let's say a player's energy is recorded in a table as "20". As he engages in mission, his energy decreases and reaches 0. However, it would be replenish back to "20" the following day. How do the database detect that a new day has arrive and then automatically assign some value in a certain table?
Store in database the time (date and hour) when energy should be restored. Then each time player logs in check if this time passed yet or not. If it has, restore the energy.
Upgrade to MySQL 5.1 and use events. http://dev.mysql.com/tech-resources/articles/mysql-events.html
for people who are using shared hosting like me, go look for "cron jobs" in your control panel and then set your automated task there.
Not at all. Call a stored procedure / execute SQL regularly from OUTSIDE the database.
Use a Trigger that'll run when your condition is verified