Is there something wrong with Gruss, the API or neither ?

[doris_day]

Since the Betfair 'upgrade' on the 26th Oct (I think it was) my version of Gruss has been acting very strangely and I'm trying to get to the bottom of what could be going on.
I am using vers 63n on 3 separate servers and in every case I'm getting the same issues. Prior to 26th Oct I have had intermittant issues and usually it has been down to the Betfair API and the issues have normally been rectified when Betfair do an upgrade. In fact the upgrade prior to the one on the 26th seemed to fix a few issues I had with refreshing but the most recent one has really left me scratching my head. All these comments relate to in-running horse racing markets only.

What I'm finding is this:

1. Intermittant refreshing. If I ask for refreshes of 0.1 sec on 2 markets I usually get around 18/sec with some variability as expected. However, I'm finding it constantly moves between 3 and 18/sec quite randomly.
2. Sticking markets. Refreshing may be doing fine, then stick for a period of time like 0.5 to 1 sec. Prices may then jump around strangely.
3. A new issue is when I get matched in-running I always got an instant number in the respective P/L cell but since the 26th (or installing 63n) this number takes a much longer time which varies in length between about 0.2 sec and 2 secs. This has never happened before.

The issues are worse at the weekends because of the soccer but its been going on during this week too.

Oher people who I know similarly use the Betfair API in a fast way have told me they aren't experiencing too many issues out of the usual, so I'm beginning to wonder if there are issues with vers 63n of BA.
My gut feeling is that its an API issue and I know Bet Trader Evolution has had release issues because of known API problems.

If this was only happening to one of my systems then I'd put it down to ISP problems but I'm getting exactly the same across all 3.

Could it be falling liquidity, BA inefficiencies, API issues, or a combination of all 3 ?

I'm absolutely not pointing the finger anywhere but am just trying to get to the bottom of what is going on. I've been doing what I'm doing now for over 2 years without these issues and need to get to the bottom of what may be going on.

If anyone has experienced any strange things since the 26th Oct, or with 63n, or hasn't seen anything different, it would be interesting to hear.

[osknows]

I'm getting the same issues 1 & 2 using version 63s. I first noticed it on Saturday 31st but only because that's when I was in front of my computer so it could have been happening earlier. It hasn't improved today

[doris_day]

Thanks for that. How about 3. ?

[osknows]

I'll check and confirm back

[Spike]

I have always had issue 3 (slow P&L column update) - I have this probelm on various versions and on both my servers and home computer. I find it to be an intermittent issue. Where necessary I work around it using the LTP to deduce wheter my best have matched and it's no big deal for me.

Recently I've started having another problem too:

When I switch to a new market it seems to be taking AGES to get the bet results- and I really do mean ages (up to a minute on a saturday, 2 or three secs during the week). The effect is that if I look at the market in BA it's continuing to refresh at 1 sec (regardless of my sheet's refresh rate) whilst if I look at my sheet it appears to be totally frozen.

I've just been living with it as it's an easy problem to adapt around and I'm sure it's a betfair issue rather than one with BA.

I wonder if you've encountered the same thing, or whether this might be the cause of your frozen markets?

[pugs]

Is it really viable to try and refresh markets at a 0.1 refresh rate?

I know BA can, and the API respond, because I have just refreshed the first race tomorrow 5000 times at 0.1 without a single failure of either price or bet refresh. But I guarantee if I tried it tomorrow in-running I would get many failures which would just push my refresh timeout above 1000ms, causing even slower refreshing when I do get the occasional refresh failures during in-running.

Just a couple of points regarding your post......your refreshing 2 markets at 0.1 which equates to 20 requests per second, if you then place a bet in, or have had a bet in and cancelled it without switching from and back to that market, your data throttle will slow your refreshing down anyway because you’re attempting to make 40 requests per second.

And the second point. If/when you do get a price refresh failure, the refresh timeout is 1000ms. That is probably why you are seeing your requests per second change dramatically, and randomly.

I could be wrong but that’s my understanding of the data and request timeout.

[pugs]

After writing the above post the “price refresh timeout” was playing on my mind. So I checked out an older pc which uses version 1.1.0.62 of BA and the “refresh timeouts” in that version can go as low as 50ms. So Gruss have changed this after version 62 but not sure when or why. But this could be something that some users with very high refresh rates are noticing.

[doris_day]

Thanks for the replies.

First off is that I've been doing what I'm doing now for a couple of years and know exactly how the API responds when things are going well. When I ask for 2 markets to refresh at 0.1 sec in-running I usually get around 16-18 per second. I never throttle my requests so throttling is not involved in this and never has. When the bet matching engine has problems keeping up like on a Saturday when there is soccer happening or the API has issues, the variability in the refresh time stands out most obviously and since last Monday 26th Oct this is what has been happening. The in-running market refreshes vary randomly from 1 to 19/sec. Most of the variability happens in the last 30 secs of the race and this is why it seems to me that the bet matching engine (or API) simply can't keep pace with the requests.
When any bet is matched the refreshes go up to around 27/sec.

I don't have the same problems as you Spike, other than the slow P/L update but I'll monitor things.

I've emailed the guys in the API department but invariably they keep tight lipped about what is going on. I read with interest that Adam Todd and his coders have had to put bug workarounds in place for his software and it seems to show that the API department at Betfair don't have the right attitude to provide a product that is 100%. They seem to think 95% is fine. That's a shame I think and pretty unprofessional.

[Spike]

Doris,

Do you get hit for data charges?

[GaryRussell]

I think the problem is the API. It's not performing at all well just lately. The P&L is updated when your bets have been updated which is a separate refresh from the prices so you will have occassions where the P&L isn't updated for several refreshes when the bets refresh gets a slow response.

You are definitely not going to like this. Betfair have asked me to throttle the requests per market to 5 per second for price refreshes and 3 per second for bet refreshes. This is obviously because the API isn't coping. It's going to be rolled out to all vendors in due course. There won't be an option to reduce this throttling. You will still be able to make over the 20 requests allowed across multiple markets, but each individual market will never be able to exceed the 5+3 requests. There hasn't been an official announcement yet, but I am pretty sure this is going to happen.

[GaryRussell]

I am going to add some code to log the individual response times of all calls so you will be able to refer back to it and also use it as evidence for Betfair when it's not performing.

[pugs]

I’m not sure, and don’t really know anything about the bet matching engine, but like you 99% of my refresh “stickiness” occurs in the last 30 seconds of a horse race, and on average 7 to 12 races per week. The recent API upgrade you mentioned in this and an earlier thread hasn’t noticeably changed anything my end, and I’m still convinced its caused by people, me included, who increase their refresh rates for in-running. Maybe it is a combination of the increased refresh rates and many more bets being fired in towards the end of a race.

Your point 3 is something I have noticed for quite some time when a horse race first goes in-running. If I have any unmatched bets my profit column can remain yellow for a few seconds whilst my grid is happily refreshing, and as the BA is refreshing “prices” and “bets” at the same time/rate then the API must be sometimes a bit slow when sending data regarding P&L. Just one point though. Are you placing all your bets via Gruss software? Because if you do place bets via another source your BA may not know you have a bet in that market for a few seconds and therefore will not start refreshing “bets” at your desired refresh rate until it does know.

[pugs]

Hello Gary, I know how busy you are but if you get chance. Was there a reason the “request timeout” needed to be changed to minimum 1000ms. Many thanks.

[GaryRussell]

With the timeout as low as 50ms it will give up after 50ms and make another request. The first request may well still get a reply which will be ignored and was therefore a wasted request to the API which it still had to process. I think that timeouts this low will just add to the strain on the API when there are performance issues so I increased it to 1 second.

[pugs]

Yes I agree, 50ms isn’t exactly what you would call a slow response time. But I was just thinking that maybe at 1000ms then high refresh users in particular may be experiencing very slightly more stickiness than just the API.