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[EP-tech] Too many connections

Hi George

                We ran into the same problem on the 11th and 19th of July. Apparently this was due to a robot/DoS issue of something hitting the repository very fast and using up all the connections.  My understanding that this sort of thing with the too many connections error should only be happening under these unusual circumstances but I'm sure others can contribute a bit more on what is an appropriate setting.


(Nottingham Uni Library)

From: eprints-tech-bounces at ecs.soton.ac.uk [mailto:eprints-tech-bounces at ecs.soton.ac.uk] On Behalf Of George Macgregor
Sent: 15 August 2016 10:20
To: eprints-tech at ecs.soton.ac.uk
Subject: [EP-tech] Too many connections

Hello colleagues.

Occasionally our EPrints suffers the "too many connections" MySQL connection error.  In the past when EPrints has suffered this error my assumption has been that there is a query hanging which then has a knock on effect on other queries as they can't write to a table.  We currently have max_connections set to 300 (which seems like a lot) but I can observe from previous chatter on the list that some go up to 1000.  I was therefore wondering what the community considered to be an appropriate connection limit?  Given all the traffic I can observe it is conceivable - however unlikely - that 300 is insufficient.  Have others observed something similar?

Thanks in advance!


George Macgregor
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