Back-ground:
Till Vsphere 6.6 or below, There is a limit of 15 disks / PVSCSI controller on a VM, but with Vsphere 6.7 the limit has been increased to 64 disks/ PVSCSI controller.
So i am trying to fetch the threshold dynamically and do some pre-checks while adding a disk to the VM. are there any Vcenter API's which can return max allowed disks for a specific controller?
Related
I created a site on App Engine and chose the smallest F1 instance class which according to the docs has a CPU Limit of 600 MHz.
I limited the app to 1 instance only as a test and let it run several days then checked the CPU utilization on the dashboard. Here's part of the chart:
As you can see the utilization which is given in Megacycles/sec which I assume equals to one MHz is between like 700 and 1500.
The app uses one F1 instance only, runs without problems, there are no quota errors, but then what does the 600 Mhz CPU limit mean if the utilization is usually above it?
Megacycles/sec is not MHz in this graph. As explained in Interface QuotaService:
Measures the duration that the current request has spent so far
processing the request within the App Engine sandbox. Note that time
spent in API calls will not be added to this value. The unit the
duration is measured is Megacycles. If all instructions were to be
executed sequentially on a standard 1.2 GHz 64-bit x86 CPU, 1200
megacycles would equate to one second physical time elapsed.
In App Engine Flex, you get an entire CPU core from the machine you are renting out, but in App Engine Standard, it shows the Megacycles since it uses a sandbox.
Note that there is a feature request in the issue tracker on adding CPU% metric under gae_app for App Engine standard and I have relayed your concern about it to the Cloud App Engine product team. However, there is no guarantee of the implementation and ETA at this time. I recommend to star the ticket so that you would receive updates about it.
I am working on IBM cloudant performance testing. ( No SQL DB hosted in IBM cloud).
I am trying to identify the breaking point ( max input/sec).
I am triggering this request (POST) with JSON data.
I am unable to determine to design this test plan and thread group.
I need to determine the breaking point ( maximum allowed request/second).
Please find my Jmeter configuration above
The test type, you're trying to achieve is the Stress Test, you should design the workload as follows:
Start with 1 virtual user
Gradually increase the load
Observe the correlation between increasing number of virtual users and the throughput (number of requests per second) using i.e. Transaction Throughput vs Threads chart (can be installed using JMeter Plugins Manager)
Ideally throughput should increase proportionally to the increasing number of threads (virtual users). However applications have their limit therefore at certain stage you will run into the situation when the number of virtual users increases and throughput decreases. The moment just before throughput degradation is called saturation point and this is what you're looking for.
P.S. 20 000 virtual users might be a little bit high number for a single JMeter engine, you might need to consider switching to Distributed Testing
I have a producer application which writes to Kinesis stream at rate of 600 records per sec. I have written an Apache flink application to read/process and aggregate this streaming data and write the aggregated output to AWS Redshift.
The average size of each record is 2KB. This application will be running 24 * 7.
I wanted to know what should be the configuration of my AWS EMR Cluster. How many nodes do i require ? What should be the EC2 instance type (R3/C3) that I should be using.
Apart from the performance aspect, cost is also important for us.
Whether to go for r3/c3 depends on a number of resources your application is using.
I assume that you are using windowing or some stateful operator to perform the aggregation. A stateful operator will maintain the state in the StateBackend configured https://ci.apache.org/projects/flink/flink-docs-release-1.3/ops/state_backends.html#state-backends
So you can first check if the state fits in memory(if you intend to use FSStateBackend) by trying out your application on c3 type instances. You can check the memory utilization using JVisualVM. Also, try to the check the CPU utilization here.
With r3 type instances, you will get more memory with the same number of CPU that c3 provides. For Ex: c3.4xlarge instances provides 16 vCPU with 30GB memory per node whereas r34xlarge provides 16vCPU with 122GB memory per node.
So, it depends on your application what type of instances you should be using.
For the price comparison you can refer this :
http://www.ec2instances.info/
JSONStore provides us with a great way to sync data with a server and track changes a user makes while offline. Is there a limit as to how much information could be saved on JSONStore? I found that Webkit database has a limit of 5 MB where as SQLLite database has no limit. Also wondering where JSONStore uses WebKit database or SQLLite to store its underlying information
JSONStore ultimately stores information on the file system. The only bounds would be the space remaining on the device or any file size limits imposed the the devices operating system. We have easily created JSONStore instances that were hundreds and hundres of MB on disk.
How to configure the RavenDB database that can be capable to sending too many requests, or receiving too large a response?
By default, RavenDB will not allow operations that might compromise the stability of either the server or the client and a RavenDB session automatically enforces the following limitations:
If a page size value is not specified, the length of the results will be limited to 128 results. At the server side as well, there is a hard limit to the page size of 1,024 results.
The number of remote calls to the server per session is limited to 30.
I want to configure DocumentStore/DocumentSession in the client that it increase limitation of page size value and number of remote calls the server per session.
You can adjust the max page size with the Raven/MaxPageSize setting as described here. You can adjust the max number of session requests via IDocumentStore.Conventions.MaxNumberOfRequestsPerSession. However, a better approach is to architect your application such that you don't need large sessions. Instead, prefer to create sessions for small unit of work and dispose them. If a certain operation requires a large number of requests, batch them into groups of 1,024 or so.