Slow response from concurrent login of users.
Hello everyone,
Firstly my apologies if this is the incorrect location to post this thread.
I'm seeking technical support at the user level for a site I've been asked to support. I'm experienced in IT support, but new to Openvpms.
I have a client with a server running Openvpms V2.0. It's a Windows 2012 box with 32gb of ram, mirrored 2TB mechanical hard drives (30% capacity used) and a quad core i7 chipset and Gb Ethernet.
The network is simple and flat - only one boarder router. Network efficiency is good - running a gigabit switch, and I've checked for device chatter, malware, and the other associated resource hogs. Copying large files across the network is completed with acceptable speed.
Situation:
The server has historically been used as a client, a practice that's changing. However, regardless of if the server is in use as a client or simply being a file share, if "more than one" person logs into the system from one of the other Windows (7 or 10) machines, the server begins to work very hard and the system slows for everyone. If three of four log in (regardless of if the server is used as a client or not) the server cpu cores will increase to nearly 95%+ utilisation on all cores and the usage experience for the logged in client machines is extremely poor to unusable.
Does Openvpms have cache settings that I can configure? The issue is presenting like a system that's being overworked, but given the spec of the server and network I think that's a symptom rather than a cause. Would a dedicated local drive on the server (to use for cache/swap) help with this issue?
Any advice appreciated.
Many thanks to all.
Re: Slow response from concurrent login of users.
Check:
Processes used by OpenVPMS include:
On a 32G system, you have room to grow. Start with 1G for Tomcat, and 4G for MySQL and see how you go.
For instructions on Tomcat memory allocation: https://stackoverflow.com/questions/5984540/how-do-i-increase-memory-on-...
For MySQL buffer sizes: https://dev.mysql.com/doc/refman/5.5/en/innodb-buffer-pool.html
Re: Slow response from concurrent login of users.
Thanks for your feedback on this. Just briefly, is there a recommended tomcat version to run with the platform? I neglected to add the site is running 8.5 currently.
Many thanks
Re: Slow response from concurrent login of users.
Tomcat 8.5 is fine.
Re: Slow response from concurrent login of users.
Another thing to check would be the MySQL slow query log.
This is disabled by default, but can be turned on to show queries taking a long time.
E.g. see https://www.a2hosting.com/kb/developer-corner/mysql/enabling-the-slow-qu...
I've just had report of a site where the slow query log was used to show that a 3rd party app was running long queries every 15 seconds or so, significantly affecting performance.
Re: Slow response from concurrent login of users.
Thank you. I'll be looking into that also. I've made the above recommendations to memory allocation, but the reoccurring issue is still persisting, albeit less frequently. I'm looking at server/network topology and general workload, and have question about how Openvpms is accessed. Is it essential that the Windows server which hosts the system, be a terminal/RD server running concurrent client sessions of Openvpms - or can a Windows client (for example) access the server ip on port 8080 and log into Openvpms via the network, or is that not considered best practice?
Although I don't yet have logging information to verify this, I'm concerned the server load is exceeding its hardware limits during peak times, leading to degraded overall performance and ultimately the failures noted. If possible, I'd like to avoid using RDS and keep share the load rather than concentrate it.
Many thanks for your advise to date.
Re: Slow response from concurrent login of users.
You could do that ie run it on the same server as RDS...I wouldnt.
I mean the whole basis of Open is its a served website..effectively by using RDS and accessing localhost the server is getting hit twice.
If I setup Open ...I would avoid that setup for exactly this reason. Generally I set it up on a linux box and run apache in front of it. This means minimal network overhead and the client machines cpu / gpu handles the browser and javascript rather than the server handling both.
I have been running it on a windows server but we only used it as an AD not as a terminal server ...even then I felt there was too much other work being done on the server and I am migrating Open to a cloud-based instance VPN'd back to the surgery... I considered a dedicated box but TCO / Maintenance meant cloud was better in our case.