Do you flush ? the Linux RAM cache buffer.
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Hi,
We have web production system, hosting an electronic medical record system, that is only used on normal working hours 8am-5pm.
We ran into issue, and we are abit uncertain it is related to memory leak of specific library (after 28 days the system gave Java exception that physical RAM is less than 3 GB thus will not run a Java command) or linux RAM caching, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
One of the possible solutions or workarounds I proposed was to schedule this command on weekly basis at night:
"sync; echo 1 > /proc/sys/vm/drop_caches"After it ran the ram cache using free -m was 14 GB and it cleared, the next day got to 6GB at the end of working day.
I know the best solution is to ensure there is not memory leak especially since we use JAVA (we are working on this with vendor), however I am asking if any of you using production systems and scheduling this command
"sync; echo 1 > /proc/sys/vm/drop_caches"
To avoid reboots? to ensure there are always free ram ? any downsides ?
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centos 6.7 and we can not update it (vendor specific)
Please tell me this isn’t public facing with a portal or something. I don’t think 6.7 even has EUS anymore since it’s past 24 months from the release.
I honestly have not had an issue like this so I can’t really give any insight.
What software is this?
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@emad-r said in Do you flush ? the Linux RAM cache buffer.:
, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
OMG - say it isn't so - you mean platforms other than Windows have this issue? I just can't believe it /sarcasm off
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
OMG - say it isn't so - you mean platforms other than Windows have this issue? I just can't believe it /sarcasm off
Sadly we have software that required something similar to be “supported”. We do internal QA of all of our software and found that being on 7.4 vs 7.3 made no difference so we updated. It actually works better on 7.4 anyway.
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@stacksofplates said in Do you flush ? the Linux RAM cache buffer.:
ted”. We do internal QA of all of our so
theoretically it should work on 6.8 but I cant make that decision.
No its not internet facing. -
It is software from software company with 5000+ employees
and are in 14 countries.It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.
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@emad-r said in Do you flush ? the Linux RAM cache buffer.:
It is software from software company with 5000+ employees
and are in 14 countries.The software is made by a company with 5000+ employees? what difference does this make?
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@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
I think he means that people are going to listen to her even if she makes bad decisions.
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@emad-r said in Do you flush ? the Linux RAM cache buffer.:
It is software from software company with 5000+ employees
and are in 14 countries.It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.
I only ask because I knew of one that ran on CentOS but never knew what version. It's probably not the one I'm thinking of.
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
How dense are you?
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@jaredbusch said in Do you flush ? the Linux RAM cache buffer.:
@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
How dense are you?
apparently pretty.
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@jaredbusch said in Do you flush ? the Linux RAM cache buffer.:
@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
How dense are you?
In reading that again - is he saying that because he's not a hot lookin' expat, that his ideas are worthless? if not, then again - I have no clue what's he's on about.
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
OMG - say it isn't so - you mean platforms other than Windows have this issue? I just can't believe it /sarcasm off
The issue is the app, not the OS.
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
@stacksofplates
It really not the vendor 100% fault, our EMR manager is semi-nice looking female + expat = that what matters where I work.I'm also not sure how this plays into it either?
He's saying he works in the real world where a hot sales girl has more sway than the IT team.
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@scottalanmiller said in Do you flush ? the Linux RAM cache buffer.:
@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
OMG - say it isn't so - you mean platforms other than Windows have this issue? I just can't believe it /sarcasm off
The issue is the app, not the OS.
Yes Scott I know... but this is generally something much more associated with Windows than other platforms. Of course this in no way implies that it never happens on other platforms...
oh and you did see the /sarcasm off part, right?
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I never use cache dropping. Any reason you don't just reboot? I mean both are pretty awful, but if this system is critical it'd be rebooting regularly anyway. Might as well do the two together.
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@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@scottalanmiller said in Do you flush ? the Linux RAM cache buffer.:
@dashrender said in Do you flush ? the Linux RAM cache buffer.:
@emad-r said in Do you flush ? the Linux RAM cache buffer.:
, the linux OS is not the latest it is centos 6.7 and we can not update it (vendor specific)
OMG - say it isn't so - you mean platforms other than Windows have this issue? I just can't believe it /sarcasm off
The issue is the app, not the OS.
Yes Scott I know... but this is generally something much more associated with Windows than other platforms. Of course this in no way implies that it never happens on other platforms...
oh and you did see the /sarcasm off part, right?
I see the sarcasm bit but don't understand it nonetheless.
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@emad-r Your flushing the kernel level block storage cache, of course there are downsides. I've not run into an issue where flushing the caches actually fixed a memory leak issue, either. All you're doing is delaying the inevitable crash.
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Did I understand correctly that it's a Java application? If so, how are you launching/running it? What CLI command you using?
