I want to write synchro check in my VBS application but starting at the very beginning i think whole NTP synchro is doesn't work.
Please, advice me how can i check this?
My network:
1 station with WindowsServer2012R2 (set as NTP Server)
6 stations with Windows10Pro (set as NTP Clients)
From Client station - when i manually press "Update Now" - from:
Date and Time / Internet Time / Change Settings / -> Update Now.
The time on client is updating.
But when set pooling interval to - for instance - every 5 minutes
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\TimeProviders\NtpClient]
"SpecialPollInterval"=dword:0000012c
When i change time during this 5 minutes, the time will be not synchronized.
Why?
I don't see any reason why it does not work?
What i am missing?
Related
I'm struggling a bit with time drift between processes on the same virtual guest
In real life - we have around 50 processes sending messages to each other and the drift
makes reading logs hard.
To illustrate my problem I am running two processes I wrote on a Windows server 2019.
Process 1 (time_client - tc ) finds out what time it is,
and then send a string representing the current time to
process 2 (server TS) via a named pipe.
The string sent looks like '23-May-2022 14:26:55.608'
printout from TS looks like
23-May-2022 13:03:29.344 -
23-May-2022 14:39:57.396 -
23-May-2022 14:39:57.492
diff is 00000:00:00:00.096
server is ahead FALSE
where diff is days:hours:minutes:seconds.milliseconds
TS - the server - does the following:
save the time when process is started
then, upon arrival of time_string from TC
get time from os
print starttime, time from os, time from TC, and diff time_from_os - time_String from TC
tc send a new time_string every minute. The TC is started at every invokation and runs to completion, so every time it is a new instance running
I notice this after ca 2 hrs
win server 2019 on VMWare
diff grows to ca 150 ms after 1 hour
win server 2016 on VMWare
diff grows to ca 50 ms after 1 hour
Linux Rocky 8.6 on VirtualBox - Host Win 10
diff grows to ca 0 ms after 2 hours
The drift between the two processes on windows is very annoying since it messes up log completely.
One process is creating an event, and send a message to another process, which treats is several seconds earlier - according to the logs.
The process are usually up for months - but for some communications processes that are restarted due to lost communication at least daily
So - it is not that the guest is out of synch - that would be ok.
It is that the processes get a different value of 'now' depending on how long they have been running.
Is this a well known problem ? Having a hard time googling it
The problem could be within VMWare or within Windows.
Spring boot project, log how many time took to save 2 DB,
long start = System.currentTimeMillis();
getDao().batchInsert(batchList);
long end = System.currentTimeMillis();
log.info("Save {} data 2 DB successfully took time: {}", getDescName(), (end - start));
Very strangely, I found there is situation time cost is negative，see below
2019-05-16 14:41:04.420 INFO 3324 --- [ave2db-thread-2] c.c.sz_vss.demo.AbstractSave2DBProcess : Save Stock data 2 DB batch size: 416
2019-05-16 14:41:03.152 INFO 3324 --- [ave2db-thread-2] c.c.sz_vss.demo.AbstractSave2DBProcess : Save Stock data 2 DB successfully took time: -1268
Why does this happen? Is it spring boot log system bug? or is it the Windows system time could retreat occasionally?
Network time synchronization can apply a correction in either direction, so yes the system calendar can move backwards. Also in timezones that observe daylight savings time, you will see +/- 1 hour discontinuities each year.
That's why it is not recommended to use the system calendar for measuring elapsed time. There are monotonic timers (on Windows, QueryPerformanceCounter() combined with QueryPerformanceFrequency(), on POSIX such as Linux it is clock_gettime(CLOCK_MONOTONIC)). Managed frameworks usually wrap these in an object named "Stopwatch".
I am getting the Socket Exception while running load test on self-provisioned test rig.
I am trigger those load tests in agent machine(self-provisioned test rig) from my local machine.
Note : For first 2 to 3 minutes test iterations are passing , after that we are getting the Socket Exception.
Below is the error message :
A connection attempt failed because the connected party did not
properly respond after a period of time, or established connection
failed because connected host has failed to respond.
Below are the stack trace details :
at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult) at
System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure,
Socket s4, Socket s6, Socket& socket, IPAddress& address,
ConnectSocketState state, IAsyncResult asyncResult, Exception&
exception)
Run Time - 20min
Sample rate - 10sec
warm up duration 10sec
number of agents used - 2
Load pattern :
initial load - 10user
max user count - 300
step duration - 10sec
step user count - 10
Although, by Changing above values I am still getting the exception in the same way.
I am using Visual studio 2015 enterprise.
The question states: start with 10 users, every 10 seconds add 10 users to a maximum of 300. Thus after 29 increments there will be 300 users and that will take 29*10 seconds which is 4m50s. The test will thus (attempt to) run with the maximum load of 300 users for the remaining 15m10s.
Given that all tests pass for the first 2 or 3 minutes plus the the error message, that suggests that you are overloading some part of the network. It might be the agents, it might be the servers or it might be on the connections between them. Some network components have a maximum number of active connections and the 300 users might be too many.
Increasing the load so rapidly means you do not clearly know what the limiting value. The sampling rate (at 10 seconds) seems high. At each sampling interval a lot of data is transferred (i.e. the sample data) and that can swamp parts of the network. You should look at the network counters for the agents and controller, also the servers if available.
I recommend changing the load test steps to add 10 users every 30 seconds, so it takes about 15 minutes to reach 300 users. It may also be worth reducing the sample rate to every 20 seconds.
I have the next test plan in JMeter:
on the screenshot you can see the settings for the 1st ThreadGroup, wich has 50% of common amout of request in test plan (in each Thread Group are 10 different subrequests placed).
So, +1 request per second is added in average using these settings.
Then I ran this test and saw this picture (Error % column):
I save errors in file and all these errors have the same text:
<sample t="30129" lt="0" ts="1356710138314" s="false" lb="WebService(SOAP) Request 1" rc="000" rm="**Connection reset**" tn="jp#gc - Stepping Thread Group1 3-247" dt="text" by="0"/>
Server's cpu screenshot:
and for database:
After the errors have appeared my comp started work slowly and slowly (although the errors stopped to appear further)...
And in the same time the server's cpu progressively dropped to 0.
Could you tell me, please,
What is the reason of this error?
Have I reached the server timeout? (Because Max is more than 30s in the table).
UPD. I have rerun test with next settings: 1000 users per 02:46:40 (+1 Thread Group per 10 second and 10 requests inside each new Thread in the Loop).
I.e. I have reduced the time of test and total Thread Groups by 2 times, but save intensivity of Thead's adding.
The results are the same (including cpu usage on the server).
I've received the error «Connection reset» after 990 thread started. There are screenshots:
Any idea?
First, WebService(SOAP) Request is not the best way to test Webservices in JMeter, it will be deprecated in upcoming 2.9 version.
HTTP Sampler is the one to choose as it performs much better.
Second, Connection Reset means your server has cut connection. It could be coming from the CPU which seems high but it's not sure.
If what you call "my comp" is the computer hosting JMeter started working slowly then your JMeter instance is overwhelmed by the number of threads (2003 or more?) you've configured. It can come from a lot of factors, read this:
http://www.dzone.com/links/see_how_to_make_jmeter_run_thousands_of_threads_w.html
I have the next test plan in JMeter:
on the screenshot you can see the settings for the 1st ThreadGroup, wich has 50% of common amout of request in test plan (in each Thread Group are 10 different subrequests placed).
So, +1 request per second is added in average using these settings.
Then I ran this test and saw this picture (Error % column):
I save errors in file and all these errors have the same text:
<sample t="30129" lt="0" ts="1356710138314" s="false" lb="WebService(SOAP) Request 1" rc="000" rm="**Connection reset**" tn="jp#gc - Stepping Thread Group1 3-247" dt="text" by="0"/>
Server's cpu screenshot:
and for database:
After the errors have appeared my comp started work slowly and slowly (although the errors stopped to appear further)...
And in the same time the server's cpu progressively dropped to 0.
Could you tell me, please,
What is the reason of this error?
Have I reached the server timeout? (Because Max is more than 30s in the table).
UPD. I have rerun test with next settings: 1000 users per 02:46:40 (+1 Thread Group per 10 second and 10 requests inside each new Thread in the Loop).
I.e. I have reduced the time of test and total Thread Groups by 2 times, but save intensivity of Thead's adding.
The results are the same (including cpu usage on the server).
I've received the error «Connection reset» after 990 thread started. There are screenshots:
Any idea?
First, WebService(SOAP) Request is not the best way to test Webservices in JMeter, it will be deprecated in upcoming 2.9 version.
HTTP Sampler is the one to choose as it performs much better.
Second, Connection Reset means your server has cut connection. It could be coming from the CPU which seems high but it's not sure.
If what you call "my comp" is the computer hosting JMeter started working slowly then your JMeter instance is overwhelmed by the number of threads (2003 or more?) you've configured. It can come from a lot of factors, read this:
http://www.dzone.com/links/see_how_to_make_jmeter_run_thousands_of_threads_w.html