How to setup frequency control?

chanro4

Hi,
I am new to Lightstreamer and have followed some demo example in Lightstreamer.
But seems I cannot find a place to set the frequency control. Any hint for me on how to setup frequency control? :Smile_Ab:

Frequency Control
A maximum update frequency can be allocated for each user/item combination. For example, it is possible to configure the profile of a certain user so that they do not receive more than 2 updates per second for a certain subscribed item (piece of data).

Mone

first of all, there are minimum limits on the frequency posed by the server edition you're running; see http://www.lightstreamer.com/products.htm

any client can ask the server to set a further limit calling a "frequency" method located on the "table" object; in the case of the web client you can call the setRequestedMaxFrequency method.

the metadata adapter may set another limit on the frequency through the getAllowedMaxItemFrequency.

HTH

chanro4

Hi,
For setRequestedMaxFrequency using in "command" or "distinct" mode, if there is any event missing at the client side if the event in frequency is faster than the max frequency allowed? (will Lightstreamer filter out some event or it will send those event later?)

@Mone, Wrote: first of all, there are minimum limits on the frequency posed by the server edition you're running; see http://www.lightstreamer.com/products.htm

any client can ask the server to set a further limit calling a "frequency" method located on the "table" object; in the case of the web client you can call the setRequestedMaxFrequency method.

the metadata adapter may set another limit on the frequency through the getAllowedMaxItemFrequency.

HTH

chanro4

And how about the Bandwidth control? Is it set in web client side? Which function should be used? (is it setRequestedBufferSize(size) )

Bandwidth Control
For each user a maximum bandwidth can be allocated, dedicated to the streaming channel, For example, if it is required that a certain user cannot exceed a bandwidth of 10 kbps, Lightstreamer will filter the data in such a way as to ensure that the streaming connection for that user always remains below 10 kbps.

Mone

the bandwith settings follows the same pattern, the client can ask to limit its bandwidth (setRequestedBufferSize is the correct method) but the server has always the right to limit it further (see getAllowedMaxBandwidth). Note that bandwidth applies to the whole connection.

about the filtering question, Lightstreamer filters the updates on the basis of the subscription mode. If the frequency of the feed is too high the server may merge updates, queue them and, if the queue is full, drop them. On some cases dropped events are notified to the client (see onLostUpdates)

Check out section 3 of the "General Concepts.pdf" file available under LS_HOME/DOCS-SDKs for a better understanding on the logic that drives the filtering.

Let us know if you need further details.