How to control various log sizes - azure-service-fabric

I have cluster running in Azure.
I have multiple gigabytes of log data under D:\SvcFab\Log\Traces. Is there way to control amount of trace data that is collected/stored? Will the logs grow indefinitely?
Also the D:\SvcFab\ReplicatorLog has 8GB of preallocated data as specified by SharedLogSizeInMB parameter (https://learn.microsoft.com/en-us/azure/service-fabric/service-fabric-reliable-services-configuration). How can I change this setting in Azure cluster or should it always be kept default?

For Azure clusters the SvcFab\Log folder will grow up to 5GB. It will also shrink if detects your disk is running out of space (<1GB). There are no controls for this in Azure.

This may be old but if you still have this issue, the solution for this is to add parameter in arm template for service fabric cluster .. there are some other ways to do this but this one is the most guaranteed one
https://techcommunity.microsoft.com/t5/azure-paas-developer-blog/reduce-log-size-on-service-fabric-node/ba-p/1017493

Related

FabricDCA and MaxDiskQuotaInMB Configuration

There's two parts to this question. First, what falls under the purview of the Diagnostics---MaxDiskQuotaInMB configuration? Is it everything under SvcFab/Log? Just SvcFab/Log/AppInstanceData/? Having more info on this would be nice.
Second, what is the proper course of action if the FabricDCA.exe is running but the SvcFab/Log and SvcFab/Log/AppInstanceData/ folders exceed the limits we've set on their size? My team set them to 10,000 MB, but SvcFab/Log regularly takes up 12-16 GB.
The cluster configuration on Azure recognizes the change to the MaxDiskQuotaInMB configuration but there seems to be no impact on the node itself. I've tried resetting FabricDCA.exe as well and so far it has not helped either (after several hours).
One node in our cluster had so much space taken up by logs (over our limit) that remaining storage space was reduced to 1 MB.
Posting a more complete answer since it may be helpful to other people.
Most of the things under SvcFab/Log folder should fall under the quota set by MaxDiskQuotaInMB. There are a few things that may not, but the majority of things that usually take disk space are included. Keep in mind also that the task cleaning the disk usually runs every 5 minutes so you may see usage go over the quota within this timeframe.
If FabricDCA.exe is not properly cleaning files from this folder it is possible that you are hitting a bug in .Net runtime where all system.threading.timers stop firing and the disk to not be cleaned because FabricDCA relies on these timers to do so.
This is the bug on the .NET core side tracking the issue: (https://github.com/dotnet/coreclr/issues/26771). It seems to happen when the machine is running out of memory intermittently.
There is an auto-mitigation added in FabricDCA in Service Fabric 7.0.
The manual mitigation is usually to kill FabricDCA.exe process.
The process should start again and after a few minutes it will start cleaning again.
You mentioned that you already tried killing FabricDCA.exe so maybe the solution above does not work for you. In this case, try taking a look at the Service Fabric cluster manifest directly, it might be the case where your new configurations seem to be accepted by the ARM template deployment but the new configuration doesn't reach the cluster manifest which is the source of truth in this case.
Update:
There was a regression introduced as part of the auto-mitigation above which caused The AppInstanceFolder to fill up the disk. This is fixed in SF version 7.0.466

Migrate to kubernetes

We're planning to migrate our software to run in kubernetes with auto scalling, this is our current infrastructure:
PHP and apache are running in Google Compute Engine n1-standard-4 (4 vCPUs, 15 GB memory)
MySql is running in Google Cloud SQL
Data files (csv, pdf) and the code are storing in a single SSD Persistent Disk
I found many posts that recomments to store the data file in the Google Cloud Storage and use the API to fetch the file and uploading to the bucket. We have very limited time so I decide to use NFS to share the data files over the pods, the problem is nfs speed is slow, it's around 100mb/s when I copying the file with pv, the result from iperf is 1.96 Gbits/sec.Do you know how to achieve the same result without implement the cloud storage? or increase the NFS speed?
Data files (csv, pdf) and the code are storing in a single SSD Persistent Disk
There's nothing stopping you from volume mounting an SSD into the Pod so you can continue to use an SSD. I can only speak to AWS terminology, but some EC2 instances come with "local" SSD hardware, and thus you would only need to use a nodeSelector to ensure your Pods were scheduled onto machines that had said local storage available.
Where you're going to run into problems is if you are currently just using one php+apache and thus just one SSD, but now you want to scale the application up and it requires that all php+apache have access to the same SSD. That's a classic distributed application architecture problem, and something kubernetes itself can't fix for you.
If you're willing to expend the effort, you can also try any one of the other distributed filesystems (Ceph, GlusterFS, etc) and see if they perform better for your situation. Then again, "We have very limited time" I guess pretty much means that's off the table.

AWS EB should create new instance once my docker reached its maximum memory limit

I have deployed my dockerized micro services in AWS server using Elastic Beanstalk which is written using Akka-HTTP(https://github.com/theiterators/akka-http-microservice) and Scala.
I have allocated 512mb memory size for each docker and performance problems. I have noticed that the CPU usage increased when server getting more number of requests(like 20%, 23%, 45%...) & depends on load, then it automatically came down to the normal state (0.88%). But Memory usage keeps on increasing for every request and it failed to release unused memory even after CPU usage came to the normal stage and it reached 100% and docker killed by itself and restarted again.
I have also enabled auto scaling feature in EB to handle a huge number of requests. So it created another duplicate instance only after CPU usage of the running instance is reached its maximum.
How can I setup auto-scaling to create another instance once memory usage is reached its maximum limit(i.e 500mb out of 512mb)?
Please provide us a solution/way to resolve these problems as soon as possible as it is a very critical problem for us?
CloudWatch doesn't natively report memory statistics. But there are some scripts that Amazon provides (usually just referred to as the "CloudWatch Monitoring Scripts for Linux) that will get the statistics into CloudWatch so you can use those metrics to build a scaling policy.
The Elastic Beanstalk documentation provides some information on installing the scripts on the Linux platform at http://docs.aws.amazon.com/elasticbeanstalk/latest/dg/customize-containers-cw.html.
However, this will come with another caveat in that you cannot use the native Docker deployment JSON as it won't pick up the .ebextensions folder (see Where to put ebextensions config in AWS Elastic Beanstalk Docker deploy with dockerrun source bundle?). The solution here would be to create a zip of your application that includes the JSON file and .ebextensions folder and use that as the deployment artifact.
There is also one thing I am unclear on and that is if these metrics will be available to choose from under the Configuration -> Scaling section of the application. You may need to create another .ebextensions config file to set the custom metric such as:
option_settings:
aws:elasticbeanstalk:customoption:
BreachDuration: 3
LowerBreachScaleIncrement: -1
MeasureName: MemoryUtilization
Period: 60
Statistic: Average
Threshold: 90
UpperBreachScaleIncrement: 2
Now, even if this works, if the application will not lower its memory usage after scaling and load goes down then the scaling policy would just continue to trigger and reach max instances eventually.
I'd first see if you can get some garbage collection statistics for the JVM and maybe tune the JVM to do garbage collection more often to help bring memory down faster after application load goes down.

Azure Service Fabric deployments consume a lot disk space

I operate an on-premise Azure Service Fabric cluster for testing purposes. It consists of three nodes, which are running on a single virtual machine (Windows Server 2012) with a 50 GB disk attached to it.
Further I set up continuous deployment from TFS release pipeline to the cluster. However after approx. 80 deployments, service fabric consumed all available disk space and further deployments fail.
Most of the space is taken by C:\ProgramData\SF\Data, which took around 28GB, while each code package has a size of ~130 MB. After I have unprovisioned many of the old deployments (manually via SF portal), only around 5GB were released. Many of the old files are still around in C:\ProgramData\SF\Data.
What is the best approach to improve this?
Why are the files from the old deployments still on disk after unprovisioning?
Is it possible to delete these files manually?
Is it possible to automate the deprovisioning?
On a production environment this situation should be relaxed anyhow (since there is only one node per machine and bigger disks). Nevertheless this would only put off the evil day. I would feel safer to avoid this situation at all.
Edit
It seems that SF is deleting the deployment packages with some delay. I checked the test cluster after one day, and all unprovisioned packages vanished finally.
It seems that SF is deleting the deployment packages with some delay. I checked the test cluster after one day, and all unprovisioned packages vanished finally.
Further I found the Unregister-ServiceFabricApplicationType Cmdlet to automate the unprovisioning process (https://msdn.microsoft.com/en-us/library/mt125885.aspx).

Google Compute Engine snapshot of instance with persistent disks attached failed

I have a working VM instance that I'm trying to copy to allow redundancy behind google load balancer.
A test run with a dummy instance worked fine, creating a new instance from a snapshot of a running one.
Now, the real "original" instance have a persistent disk attached and this cause a problem in starting up the cloned instance because of the (obviously) missing persistent disk mount.
Logs from serial console output is as:
* Stopping cold plug devices[74G[ OK ]
* Stopping log initial device creation[74G[ OK ]
* Starting enable remaining boot-time encrypted block devices[74G[ OK ]
The disk drive for /mnt/XXXX-log is not ready yet or not present.
keys:Continue to wait, or Press S to skip mounting or M for manual recovery
As I understand there is no way to send any of this key strokes to the instance, is there any other way to overcome this issue? I know that I could unmount the disk before the snapshot, but the workflow I would like to instate is creating period snapshots of production servers, so un-mounting disks every time before performing it would require instance downtime (plus all the unnecessary risks of doing an action that would seem pointless).
Is there a way to boot this type of cloned instances successfully, and attach a new persistence disk afterwards?
Is this happening because the original persistent disk is in use, or the same problem would occur even if the original instance is offline (for example due to a failure in which case I would try to created a new instance from a snapshot)?
One workaround that I am using to get away from the same issue is that I dont't actually unmount the disk rather just comment out the the mount line in /etc/fstab and take the snapshot. This way my instance has no downtime or down disks while snapshoting. (I am using Ubuntu 14.04 as OS if that matters)
Later I fix and uncomment it when I use that snapshot on a new instance.
However you can also look into adding the nofail option in the commented line to get a better solution.
By the way I am doing a similar task building a load balanced setup with multiple webserver nodes. Each being cloned from the said snapshot with extra persistent disks mounted for eg uploads,data and logs etc
I'm a little unclear as to what you're trying to accomplish. It sounds like you're looking to periodically snapshot the data volumes of a production server so you can clone them later.
In all likelihood, you simply need to sync and fsfreeze to before you make your snapshot, rather than just unmounting/remounting it. The GCP documentation has a basic example of this in the Snapshots documentation.