Hello,
Simply speaking: you paid for 500 symbols and you receive 500 symbols.
It is that simple.
If you buy Fiat do not expect it to be Bugatti Veyron.
a) you are not allowed to exceed your subscription limits with IQFeed.
IQFeed simply won't allow you to get data for more symbols at the same time
(subscription to any more symbols will simply fail and you won't get data)
b) if you exceed the subscription limit AmiBroker will unsubscribe
oldest symbol
(the one that was accessed first) and subscribe new and will request
backfill,
BUT .... because the backfill from IQFeed is SLOW, IQFeed is literally
unable to
keep up with exploration or any automatic scan.
IQFeed (and many other RT sources) takes many seconds to backfill ONE symbol
(as IQFeed was designed to display CHARTS, not to perform whole market
scans)
and is designed with "manual", i.e. *SLOW* operation in mind (so you
manually select the chart
and watch it) - the way how QuoteTracker works - MANUALLY (slowly)
adding/removing symbols
instead of running automated scans on huge portfolios.
AmiBroker on the other hand is able to scan thousands of symbols in one
second, therefore
IQFeed is not able to deliver data fast enough (via backfill) if you exceed
subscription limits. Becuase of the time IQFeed needs to do the backfill
(if you exceed subscription counts),
you may end up with data holes (if you exceed the subscription limit).
Why do you expect receiving more data that you paid for ?
Best regards,
Tomasz Janeczko
amibroker.com
On 2010-05-14 22:12, kurasake wrote:
> I'm running AB 5.30pro using IQFeed as my RT data feed on a Core i7 w/4gig
> ram.
>
> In a different post, I'd been describing a problem I've been having when
> performing an exploration on a large number of symbols. The problem was that
> if I scanned too many symbols, I would start to get bad data appearing in AB.
>
> After some feedback, it appears that this problem occurs when I've scanned
> more symbols then what my contract with IQFeed allows. In other words, my
> contract with IQFeed allows me to monitor 500 symbols simultaneously at a
> time and if I exceed that 500 symbol limit, I would start getting bad data in
> AB. I haven't confirmed this "scientifically" yet but the problem does seem
> to happen after I've scanned somewhere in the neighborhood over 500 symbols.
>
> The question I have though is if I've only "looked" at a symbol in AB and I'm
> not actively monitoring it, like say in the Realtime Quote window, should AB
> still be holding on to an IQFeed "slot"/resource/token? I would think that
> if I'm not actively collecting data on a symbol and I've only "looked" at it
> for a brief moment, that AB should release this slot back to IQFeed. Or is
> AB still collecting data on that symbol even if it's not in the Realtime
> Quote window?
>
> If I open up the IQFeed Connection Manager, I can see how many symbols IQFeed
> is "tracking" for me. Every time I click on a symbol in AB and it backfills
> that symbol with data, the Number of Symbols counter in the IQFeed Connection
> Manager goes up. The counter however, never appers to go down unless I
> either break the connection from AB to the IQFeed client or I exit from AB.
>
> This puts a rather strong restriction on how I use AB as I can only
> scan/explore/look at 500 symbols in a single AB session and IQFeed thinks I'm
> using up my entire allotment when I'm not.
>
> Incidentally, if I run QuoteTracker on the same machine and have it connect
> to the same IQFeed client, it will "release" an IQFeed slot for every symbol
> I remove from the active QT portfolio. So it should be possible to do this
> in AB as well.
>
> If I perform a Reconnect or Shutdown from AB by right clicking in the status
> bar where it displays the client connection status, the IQFeed symbol count
> drops back down to what it was before I started AB. Does anyone know if
> there's any way to do this "reset"/release using COM objects or other
> programming means? Maybe I can write a vb script or something that keeps
> calling this obj method? Or is this a feature request that I need to place
> with AB?
>
> Many thanks.
>
>
>
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