5 ms·

> if the music starts in two hundred milliseconds or less—about half the time it takes, on average, to blink—people don’t seem to perceive a delay Anyone know

> if the music starts in two hundred milliseconds or less—about half the time it takes, on average, to blink—people don’t seem to perceive a delay Anyone know how spotify may have achieved this? My instinct is that they pre-download the next song in the queue + heavily cache everything. But in my experience, playing a new song in almost instantaneous too.

deleted 11y ago
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moe 11y ago
200ms latency Anyone know how spotify may have achieved this? There is no magic in this. 200ms is an eternity and would actually be considered rather poor performance. Realistic latency is closer to 100ms for a cache miss (~40ms for your client to reach spotify plus another 40-60ms for their internal fetch). You have to realize that music files are tiny and consume very little bandwidth by today's standards. All commercial music combined (roughly 30 million songs) fits into half a rack of storage.
- Agathos 11y ago
  While we're at it, why are we being told that the average human blink takes 400 msec? That's a pretty slow blink.
- Jarred 11y ago
  It's more challenging considering that most of Spotify's traffic is P2P.
  - moe 11y ago
    most of Spotify's traffic is P2P. They shut that down last year; https://torrentfreak.com/spotify-starts-shutting-down-its-massive-p2p-network-140416/ https://torrentfreak.com/spotify-starts-shutting-down-its-ma...
nemothekid 11y ago
200ms seems like a long time to me. From what I know, if your database takes longer than 100ms to return a query, theres something wrong[1] and CDNs have pretty much solved that "I need to get this static file around the world quickly." With just an song id, with S3/Cloudfront and [db of choice] I don't think it would be hard to deliver a song in less than 200ms (to the continental US atleast). [1] http://www.sqlskills.com/blogs/paul/are-io-latencies-killing-your-performance/ http://www.sqlskills.com/blogs/paul/are-io-latencies-killing... - Random article, I'm not sure where I picked it up from, but I've come to believe >100ms db latencies should be rare and when it happens, you messed up somewhere.

deleted 11y ago

[deleted]

moe 11y ago

200ms latency Anyone know how spotify may have achieved this? There is no magic in this. 200ms is an eternity and would actually be considered rather poor performance. Realistic latency is closer to 100ms for a cache miss (~40ms for your client to reach spotify plus another 40-60ms for their internal fetch). You have to realize that music files are tiny and consume very little bandwidth by today's standards. All commercial music combined (roughly 30 million songs) fits into half a rack of storage.

Agathos 11y ago
While we're at it, why are we being told that the average human blink takes 400 msec? That's a pretty slow blink.
Jarred 11y ago
It's more challenging considering that most of Spotify's traffic is P2P.
- moe 11y ago
  most of Spotify's traffic is P2P. They shut that down last year; https://torrentfreak.com/spotify-starts-shutting-down-its-massive-p2p-network-140416/ https://torrentfreak.com/spotify-starts-shutting-down-its-ma...

nemothekid 11y ago

200ms seems like a long time to me. From what I know, if your database takes longer than 100ms to return a query, theres something wrong[1] and CDNs have pretty much solved that "I need to get this static file around the world quickly." With just an song id, with S3/Cloudfront and [db of choice] I don't think it would be hard to deliver a song in less than 200ms (to the continental US atleast). [1] http://www.sqlskills.com/blogs/paul/are-io-latencies-killing-your-performance/ http://www.sqlskills.com/blogs/paul/are-io-latencies-killing... - Random article, I'm not sure where I picked it up from, but I've come to believe >100ms db latencies should be rare and when it happens, you messed up somewhere.