Author Topic: feed price should expired over 1 hour  (Read 4612 times)

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Offline roadscape

Thanks for clearing it up.. makes sense.. for now, I've put in the following settings, and the script runs twice per hour.

maxAgeFeedInSeconds = 24*60*60
change_min = 0.5
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Offline xeroc

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So long as your feed doesn't expire, the time in-between publishing is inconsequential. 

Publishing every minute,  every hour, every 4 hours, 8 hours, or 24 hours makes no difference, if the the actual price has not changed.

Your script should be checking the price often but only publishing if its changed some fraction of a percent from your last published price.

If the feed expires after 24 hours, at a minimum you should obviously publish at least every 24 hours.  More often only when the price has changed.

So then:
Code: [Select]
maxAgeFeedInSeconds          = 23*59*50  # A feed should be at most 1hour old
change_min                                = 0.5    # Percentage of price change to force an update

Xeldal

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So long as your feed doesn't expire, the time in-between publishing is inconsequential. 

Publishing every minute,  every hour, every 4 hours, 8 hours, or 24 hours makes no difference, if the the actual price has not changed.

Your script should be checking the price often but only publishing if its changed some fraction of a percent from your last published price.

If the feed expires after 24 hours, at a minimum you should obviously publish at least every 24 hours.  More often only when the price has changed.
« Last Edit: December 06, 2015, 10:22:24 pm by Xeldal »

Offline xeroc

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I think we may have misunderstood BM earlier.

It is required for settlements that there is at least one feed per 24h .. but for margin calls and 'fair price' we need it more accurate.

However I cant tell you a 'good number'. I. Bts1 I ran the script every 9minutes and had a max age of 15minutes for my feeds

Offline roadscape

bm and i highly recommend to publish prices more often than just once per hour .. if you want to spare money you can increase the maxage in the script but still run it frequently to catch up with price movements

Did the recommendation change? I thought it was stated before that 24 hours was sufficient and it also helped prevent market manipulation.. just want to make sure I understand
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Offline xeroc

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Price feeds EXPIRE after 24h .. this setting can be adjusted by the committee for each asset individually ..

bm and i highly recommend to publish prices more often than just once per hour .. if you want to spare money you can increase the maxage in the script but still run it frequently to catch up with price movements

Offline roadscape

I was under the impression that in 2.0 price feeds only need to be updated once per day.
I also thought that a lagging feed had security benefits.. is that not the case?

Also, someone mentioned that BTC38 was blocking them due to rate limiting.. IMO this is a good reason for easing up on feed frequency. (When you don't have permission to scrape someone's site it's best to be conservative... for more than 1 reason)
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Offline abit

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now we have 17 witness, about 11 witness published price at 0.02, but the mdedian price is still 0.0216,
because there are almost 13 wintess don't update price over 1 hour
some of them are voted out, so they can't publish price any more
so you'd better use the price published in 1 hour, or exclude the unactive witness's price

Technically it can be done with a committee proposal. Here are options in bitasset_data:
Code: [Select]
    "options": {
      "feed_lifetime_sec": 86400,
      "minimum_feeds": 7,
      "force_settlement_delay_sec": 86400,
      "force_settlement_offset_percent": 0,
      "maximum_force_settlement_volume": 200,
      "short_backing_asset": "1.3.0",
      "extensions": [

      ]
    },
It seems that current setting is 24 hours.
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Offline taoljj

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Updated.

I also encourage all witnesses to run the script often .. something between every 5 to 10 minutes (depending in the threshold limits of the exchanges)
For those not knowing: The price feed will only be published if it is of by 0.5% compared to YOUR last price or if the price is too old (15min)


delegate.taolje witness runs  feeds script every 5 minutes.

I'm sorry to update late.

Vote for delegate.taolje for witness!Thanks

Please check your script config (especially Change Max). Yours is 12 hours old now.
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Offline maqifrnswa

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sorry about that, just turned it on for the first time last night (see other post) and the cron job didn't run while I was asleep. fixed now
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Offline clayop

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I also encourage all witnesses to run the script often .. something between every 5 to 10 minutes (depending in the threshold limits of the exchanges)
For those not knowing: The price feed will only be published if it is of by 0.5% compared to YOUR last price or if the price is too old (15min)


delegate.taolje witness runs  feeds script every 5 minutes.

I'm sorry to update late.

Vote for delegate.taolje for witness!Thanks

Please check your script config (especially Change Max). Yours is 12 hours old now.
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Vote for me and see Korean Bitshares community grows
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