We have continuously over the last 6 weeks experienced random slowdowns in our e-conomic system. Due to these slowdowns, You, our customers are experiencing unavailability or slow performance of our system. We’re focusing together with our hosting partner to solve the problems, and using external database experts from two different vendors in Denmark. We have been developing logging tools to help us getting more information out of the system, so we can be better at pinpointing the slow-down cause.
The problem being random means that we have no possibilities correlating the slowdown to other scheduled activities, hence making it more difficult to find and solve the problem. The slowdown has occured in the middle of the day, at night and on a Sunday morning – so even the time of day has no influence on the situation ;-). This past Monday we had a database expert identifying further possible solutions which we deployed the night between april 1st-2nd.
1) Max degree of parallelism was set from default (=0) to 4, and
2) ‘read_committed_snapshot on’ was set followed by ‘with rollback immediate’, and
3) we added 9 additional databasefiles to the PRIMARY filegroup
It is still too early to say whether they have killed the performance slowdown bug, but after 2,5 days of good performance and no measuable slowdowns, a small hope is surfacing.
We are of cause regretting more than anyone the situation we’ve had, and will continue to monitor and improve the availability and performance.