When does velocity fetch data from server ?

Tarakeshwar NC shared this question 19 months ago
Answered

Assuming symbol is already activated in velocity (say during previous run of amibroker), then does it fetch data of these symbols as soon as market opens? OR is it that only after particular symbol is chosen in the amibroker chart it starts fetching for that sybmol?

Best Answer
photo

Good Question!

Data is fetched on demand. So only the incremental data (in addition to that which is present in velocity) is requested from the server. However, Velocity has to keep checking if there is any new data available at any time.


Basically, the complete data is fetched only once Velocity receives a demand from any TA software or application.

Comments (5)

photo
1

Good Question!

Data is fetched on demand. So only the incremental data (in addition to that which is present in velocity) is requested from the server. However, Velocity has to keep checking if there is any new data available at any time.


Basically, the complete data is fetched only once Velocity receives a demand from any TA software or application.

photo
1

If I use https://truedata.in/feedback/knowledge-base/article/how-we-can-backfilling-all-symbols-at-once (Buy=1) script for updating 60-70 symbols (1m bars) , I have noticed that it takes 2-3 mins and amibroker throws a message (plug in may be slow) and data on the chart (e.g, NIFTY-I) starts lagging compared to trading terminal even after the end of scan operation. If I run the same script on 10-20 symbols there is no lag. This is a major hurdle to run scanning scripts during market hours.

My ambroker version: 6.20 Pro Firewall OFF.

Can you please try it and suggest if any thing can be done ?

photo
1

The first time you run the scan, the historical data gets downloaded into Amibroker. You need to give it time so that the historical data is downloaded and then start using RT data. Subsequent scans during Live market should not be a problem once the history is downloaded into Amibroker.

At the end of the scanning operation, there should not be a lag though. What is the frequency of the real-time scans that you are running? However, this should not be a problem, unless Amibroker is excessively loaded with historical data. In case it is, Amibroker could slow down real-time updates as the data starts piling up into it through the day.

photo
1

Once in 2 Mins. approx 60 symbols.

Currently, Iam doing a tedious procedure of going through symbol-by-symbol in the amibroker symbol list before market and then run my script. Even then,when I notice that NIFTY-I chart starts lagging then I restart the amibroker. But then again same process of going symbol by symbol.


Will the following help?

Add all required symbols to a real time quote window thereby forcing data fetch from the server.


thx.

photo
1

RT Quote window addition will not fetch the history. However, we understand your pain point and are working on a solution at our end.

We will update you on this.

photo