[OSM-talk] Some tiles not rendering?
Svavar Kjarrval
svavar at kjarrval.is
Thu Apr 14 17:19:27 BST 2011
Enhancing the queue is not meant neccesserily to make it longer.
Although I should've referred to the queueing process to be more clear.
As Andrew pointed out, a really long queue can cause latency issues in
regards to rendering so that's not such a good idea. There are at least
two ways to counteract the problem:
1. Instead of rejecting rendering requests due to a full queue,
implement a secondary queue which will feed the primary queue when it's
not too busy. If someone requests a re-render of a tile in the secondary
queue (and the primary queue is not full), the tile request is deleted
from the secondary queue.
2. Enhance the rendering process so the queue is processed quicker.
With regards,
Svavar Kjarrval
On 04/14/2011 03:37 PM, Ian Dees wrote:
> How would you enhance the queue? Make it longer? How much longer?
>
> On Thu, Apr 14, 2011 at 10:29 AM, Svavar Kjarrval <svavar at kjarrval.is
> <mailto:svavar at kjarrval.is>> wrote:
>
> Why is the queue not enhanced to avoid instances where
> tile-rendering queries are rejected due to a full queue?
>
> With regards,
> Svavar Kjarrval
>
> On 04/14/2011 03:15 PM, Peter Wendorff wrote:
>
> Hi Nakor.
> As far as I know the queue is the whole knowledge about tiles
> which have to be rerendered.
> If a tile has to be rerendered due to a changeset, that tile
> is submitted to the queue exactly once, at the time the queue
> management reads that changeset.
> If the queue is full at that time, it's in fact not added -
> and not added later, too.
>
> An empty queue at night does not help if there is no call to
> add your tile to the queue.
>
> regards
> Peter
>
> Am 14.04.2011 16:52, schrieb Nakor:
>
>
>
> Also from the graph it looks like the queue when
> almost empty during the past 24 hours so why would
> the tile not be rendered in that case?
>
>
> Really? The queue has been full 18 hours a day or
> more for the past two weeks.
>
> Bob
>
>
> Sorry I was not clear "The queue went almost empty (for
> some time) during the past 24 hours" would have been more
> correct.
>
> That still leaves 6 hours where the queue is close to
> empty as seen on the graph for today between 0:00 and 6:00
> approximately. If there are tiles waiting to be rendered
> why do not they get processed during that time?
>
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