Hello Tangoers!
I am facing a quite strange problem since I increased the number of devices from which TDB archivers collect data.
So I have 5 instances of tdbArchiver and each of them has one device assigned.
Then I have 3 instances of a dummy device server, which consists of 18 attributes(9 have 100msec delay and other 9 have 200msec delay on read).
Archiving was defined on all atributes of these 3 instances one by one - gathering data periodicaly 1000msec. [3rd_device.png]
As long as I was using only 3 of devices, data was collected as quite normal. So I decided to add 4th instance with a same delayed device. But started getting timeouts while Starting archiving. [4th_device.png]
After about 8th click on Start button it managed to start archiving of all atributes.
Then I added 5th device and same scenario. But I got a very strange error message on the logs. Appeared only ones or twice. [error_message.png]
After all I also managed to start archiving on 5th dummy instance (had to click Start button like 10 times).
But what is the most interesting suddenly archivers was collecting data not using a periodical way of 1000msec, but sometimes even 6-9minutes to archive attribute’s value. I managed to notice it, because I increase the value which is returned by attibute by 1 on read.
[delayed_archiving.png]
As you can see on the screen above: Read was done about 14:11 and next 14:17. (The red line) Value was increased using Jive at about 14:12-14:13.
Maybe you can point me, what do I do wrong? How to solve the problem when we have to archive data on devices, which returns its data after 100-200msec on read?
In the very beginning I was using one instance of TdbArchiver which had like 10 archiver devices defined, but it all was running inside one instance process and I couldn’t even start the archivig on more devices because of timeouts which I was getting.
This is configuration of my environment:
Tango 8.1.2
Archiver 15.2.1
PyTango 8.1.6
Python 2.7.14
Windows 10