Changes between Initial Version and Version 1 of Ticket #1678, comment 1


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Timestamp:
11/21/18 14:28:44 (3 years ago)
Author:
Maxim Dounin

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  • Ticket #1678, comment 1

    initial v1  
    55It seems to be an unfortunate effect of the limits configured and the fact that virtual machine uses non-precise timers. This is because `limit_rate` limits both average and immediate download rate, and while limiting immediate download rate it uses timers to delay further sending. If the delay time calculated is only several milliseconds (12ms in the configuration provided, as sending of 64k output_buffers is expected take at least 12ms with the speed configured), and the timer is fired later than specified, then sending in small chunks may result in smaller speed than specified.
    66
    7 To improve accuracy of `limit_rate` with high rates, you may consider using larger buffers ([http://nginx.org/r/proxy_buffers proxy_buffers], [http://nginx.org/r/output_buffers output_buffers], and/or using [http://nginx.org/r/sendfile sendfile] with disk buffering.
     7To improve accuracy of `limit_rate` with high rates, you may consider using larger buffers ([http://nginx.org/r/proxy_buffers proxy_buffers], [http://nginx.org/r/output_buffers output_buffers], and/or using [http://nginx.org/r/sendfile sendfile] with disk buffering).
    88
    99(Please also note that average download rate limiting uses time with seconds resolution, and may be very inaccurate on short downloads, such as 3 seconds in your second `/limit_rate_buffering_plus_zero_temp` test.)