I use JProfiler to measure Memory used, CPU and Garbage collection for my application. I can see all those measurement in JProfiler GUI. Also I am able to store data for all mentioned measurements in disk after finishing the test using options in GUI in order to generate a nice report using excel for example.
But I want to do the same task automatically, for example when the test complete I want to store all measurement automatically in disk without using GUI.
Any help?
Thank you
Ibrahim
This is done with offline profiling.
In the "Triggers" section of the session settings, you can set up triggers that are executed for certain events, such as entry / exit of selected methods, timers, low heap / high CPU conditions, JVM start and exit and others.
Each trigger has a list of actions that control the profiling agent. Among other things, they can start and stop recording and save snapshots.
You can then export data from the saved snapshots programmatically with the command line utility jpexport.
Related
I need a Java flight recording to diagnose a performance problem on production Weblogic servers. I'd like to also get the Weblogic events. Is there any difference between starting the flight recording from either Java Mission Control (or in my case JCMD) versus initiating a WLDF diagnostic image capture? I understand the WLDF contains zipped files in addition to the .jfr, but right now I'm only interested in the flight recording (.jfr) with both the HotspotJVM and Weblogic events.
The reason I ask is because I notice something in the WLDF docs called Configure WLDF diagnostic volume (off, low, medium, high) where you set what types of Weblogic events you want to record. Will starting a flight recording from JCMD on a weblogic java instance include the Weblogic events at the preconfigured diagnostic volume? Or do you need to start it from the Weblogic Admin Console?
There is no mechanism in WLS that continuously polls to see if a recording has been started, using jcmd or JMC, and if so enable the WLDF events.
You have to enable them separately in the WLDF GUI [1]. When you do that you will also get JVM events roughly corresponding to what you get when you create a default recording. If you want more detailed information (profile), you need to start two seperate recodings.
[1] It can be good to know that the WLDF events are added using bytecode instrumentation, so the events are not even in the code until you enable the diagnostic feature.
Everything recorded into the flight recorder is recorded into the same buffers. See http://hirt.se/blog/?p=370. That said, the WLDF instrumentation settings will throttle what is actually recorded. So, there are various different ways to achieve what you want. The first thing to do is to make sure that you've enabled the diagnostic volume in WLDF to record whatever you want the WLDF to record into the flight recorder. For example "high".
Next you can either:
Start a continuous recording using command line flags, with a template configured to record you are interested in. (For example, the profiling template minus the full thread stack dump events.)
...or use jcmd to start a recording, again referring to the template that specify what, in addition to the WLDF events, you want to record.
...or use JMC to do pretty much the same thing - start a recording with the template settings you are interested in.
The advantage of the first alternative is that the events you are interested in will always be available, even if you dump an arbitrary time period. In the other two alternatives, they will only be available for the time you are running your (presumably) time limited recording. The advantage of the other alternatives is that you only pay for the (usually tiny) additional overhead of the additional events when your recordings are running.
Anyone know how can I watch my SQL Server resource usage in my windows server?
I'm using SQL Server 2016 express and especially I want to watch my ram usage if possible.
For example there is maximum ram value 1410 MB per instance for SQL Server 2016 Express. How can I know if I am close to limitations of my SQL Server or not?
Thank you.
If you are running Microsoft Windows server operating system, use the System Monitor graphical tool to measure the performance of SQL Server. You can view SQL Server objects, performance counters, and the behavior of other objects, such as processors, memory, cache, threads, and processes. Each of these objects has an associated set of counters that measure device usage, queue lengths, delays, and other indicators of throughput and internal congestion.
Note: System Monitor replaced Performance Monitor after Windows NT 4.0.
Benefits of System Monitor
System Monitor can be useful to monitor Windows operating system and SQL Server counters at the same time to determine any correlation between the performance of SQL Server and Windows. For example, monitoring the Windows disk input/output (I/O) counters and the SQL Server Buffer Manager counters at the same time can reveal the behavior of the entire system.
System Monitor allows you to obtain statistics on current SQL Server activity and performance. Using System Monitor, you can:
View data simultaneously from any number of computers.
View and change charts to reflect current activity, and show counter values that are updated at a frequency that the user defines.
Export data from charts, logs, alert logs, and reports to spreadsheet or database applications for further manipulation and printing.
Add system alerts that list an event in the alert log and can notify you by issuing a network alert.
Run a predefined application the first time or every time a counter value goes over or under a user-defined value.
Create log files that contain data about various objects from different computers.
Append to one file selected sections from other existing log files to form a long-term archive.
View current-activity reports, or create reports from existing log files.
Save individual chart, alert, log, or report settings, or the entire workspace setup for reuse.
Note: System Monitor replaced the Performance Monitor after Windows NT 4.0. You can use either the System Monitor or Performance Monitor to do these tasks.
System Monitor Performance
When you monitor SQL Server and the Microsoft Windows operating system to investigate performance-related issues, concentrate your initial efforts in three main areas:
Disk activity
Processor utilization
Memory usage
Monitoring a computer on which System Monitor is running can affect computer performance slightly. Therefore, either log the System Monitor data to another disk (or computer) so that it reduces the effect on the computer being monitored, or run System Monitor from a remote computer. Monitor only the counters in which you are interested. If you monitor too many counters, resource usage overhead is added to the monitoring process and affects the performance of the computer that is being monitored.
To start System Monitor in Windows
On the Start menu, point to Run, type perfmon in the Run dialog box, and then click OK.
More information here and here and a detailed PDF here.
It's here what I was looking for;
SELECT COUNT() AS buffer_cache_pages, COUNT() * 8 AS buffer_cache_used_KB FROM sys.dm_os_buffer_descriptors;
Is it possible to notify an application running on a Google Compute VM when the VM migrates to different hardware?
I'm a developer for an application (HMMER) that makes heavy use of vector instructions (SSE/AVX/AVX-512). The version I'm working on probes its hardware at startup to determine which vector instructions are available and picks the best set.
We've been looking at running our program on Google Compute and other cloud engines, and one concern is that, if a VM migrates from one physical machine to another while running our program, the new machine might support different instructions, causing our program to either crash or execute more slowly than it could.
Is there a way to notify applications running on a Google Compute VM when the VM migrates? The only relevant information I've found is that you can set a VM to perform a shutdown/reboot sequence when it migrates, which would kill any currently-executing programs but would at least let the user know that they needed to restart the program.
We ensure that your VM instances never live migrate between physical machines in a way that would cause your programs to crash the way you describe.
However, for your use case you probably want to specify a minimum CPU platform version. You can use this to ensure that e.g. your instance has the new Skylake AVX instructions available. See the documentation on Specifying the Minimum CPU Platform for further details.
As per the Live Migration docs:
Live migration does not change any attributes or properties of the VM
itself. The live migration process just transfers a running VM from
one host machine to another. All VM properties and attributes remain
unchanged, including things like internal and external IP addresses,
instance metadata, block storage data and volumes, OS and application
state, network settings, network connections, and so on.
Google does provide few controls to set the instance availability policies which also lets you control aspects of live migration. Here they also mention what you can look for to determine when live migration has taken place.
Live migrate
By default, standard instances are set to live migrate, where Google
Compute Engine automatically migrates your instance away from an
infrastructure maintenance event, and your instance remains running
during the migration. Your instance might experience a short period of
decreased performance, although generally most instances should not
notice any difference. This is ideal for instances that require
constant uptime, and can tolerate a short period of decreased
performance.
When Google Compute Engine migrates your instance, it reports a system
event that is published to the list of zone operations. You can review
this event by performing a gcloud compute operations list --zones ZONE
request or by viewing the list of operations in the Google Cloud
Platform Console, or through an API request. The event will appear
with the following text:
compute.instances.migrateOnHostMaintenance
In addition, you can detect directly on the VM when a maintenance event is about to happen.
Getting Live Migration Notices
The metadata server provides information about an instance's
scheduling options and settings, through the scheduling/
directory and the maintenance-event attribute. You can use these
attributes to learn about a virtual machine instance's scheduling
options, and use this metadata to notify you when a maintenance event
is about to happen through the maintenance-event attribute. By
default, all virtual machine instances are set to live migrate so the
metadata server will receive maintenance event notices before a VM
instance is live migrated. If you opted to have your VM instance
terminated during maintenance, then Compute Engine will automatically
terminate and optionally restart your VM instance if the
automaticRestart attribute is set. To learn more about maintenance
events and instance behavior during the events, read about scheduling
options and settings.
You can learn when a maintenance event will happen by querying the
maintenance-event attribute periodically. The value of this
attribute will change 60 seconds before a maintenance event starts,
giving your application code a way to trigger any tasks you want to
perform prior to a maintenance event, such as backing up data or
updating logs. Compute Engine also offers a sample Python script
to demonstrate how to check for maintenance event notices.
You can use the maintenance-event attribute with the waiting for
updates feature to notify your scripts and applications when a
maintenance event is about to start and end. This lets you automate
any actions that you might want to run before or after the event. The
following Python sample provides an example of how you might implement
these two features together.
You can also choose to terminate and optionally restart your instance.
Terminate and (optionally) restart
If you do not want your instance to live migrate, you can choose to
terminate and optionally restart your instance. With this option,
Google Compute Engine will signal your instance to shut down, wait for
a short period of time for your instance to shut down cleanly,
terminate the instance, and restart it away from the maintenance
event. This option is ideal for instances that demand constant,
maximum performance, and your overall application is built to handle
instance failures or reboots.
Look at the Setting availability policies section for more details on how to configure this.
If you use an instance with a GPU or a preemptible instance be aware that live migration is not supported:
Live migration and GPUs
Instances with GPUs attached cannot be live migrated. They must be set
to terminate and optionally restart. Compute Engine offers a 60 minute
notice before a VM instance with a GPU attached is terminated. To
learn more about these maintenance event notices, read Getting live
migration notices.
To learn more about handling host maintenance with GPUs, read
Handling host maintenance on the GPUs documentation.
Live migration for preemptible instances
You cannot configure a preemptible instances to live migrate. The
maintenance behavior for preemptible instances is always set to
TERMINATE by default, and you cannot change this option. It is also
not possible to set the automatic restart option for preemptible
instances.
As Ramesh mentioned, you can specify the minimum CPU platform to ensure you are only migrated to an instance which has at least the minimum CPU platform you specified. At a high level it looks like:
In summary, when you specify a minimum CPU platform:
Compute Engine always uses the minimum CPU platform where available.
If the minimum CPU platform is not available or the minimum CPU platform is older than the zone default, and a newer CPU platform is
available for the same price, Compute Engine uses the newer platform.
If the minimum CPU platform is not available in the specified zone and there are no newer platforms available without extra cost, the
server returns a 400 error indicating that the CPU is unavailable.
I'm trying to monitor a Java Application over a long period of time.
I want to automatically take a Thread dump or Heap Dump if number of threads or Heap exceeds some threshold.
Is this functionality available via VisualVM or Mission Control or other profiling tool?
Start the JMX Console in Java Mission Control
Go to the Triggers tab and select trigger rule "Thread Count" or "Live Set". You can select threshold and action to take. If running JDK 8, I think you can invoke a diagnostic command, such as Thread.print. It's also possible to dump a Flight Recording, which contains thread dumps among many other things.
for Java I am using VisualVM to monitor CPU, Memory, Thread info. Is there a way from VisualVM to collect this information for a range of time so that i am able to present it in a graph.
In VisualVM under Monitor tab i am able to see CPU,Classes,Heap and thread graph. I would like to be able to collect this data over a period of time when i run my load test. Later on present it on graph for later analysis.
If VisualVM is not the tool please suggest alternate option.
Thanks
You can use Tracer plugin for monitoring. Select probes which suits your needs and you should be able to export monitored data, which can be used to construct the graph of your choice.