guacamole-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael Jumper (JIRA)" <>
Subject [jira] [Resolved] (GUACAMOLE-172) Calculation of processing lag (potentially) incorrect
Date Wed, 25 Jan 2017 07:30:28 GMT


Michael Jumper resolved GUACAMOLE-172.

> Calculation of processing lag (potentially) incorrect
> -----------------------------------------------------
>                 Key: GUACAMOLE-172
>                 URL:
>             Project: Guacamole
>          Issue Type: Bug
>          Components: libguac, RDP, VNC
>            Reporter: Michael Jumper
>            Assignee: Michael Jumper
>            Priority: Critical
>             Fix For: 0.9.12-incubating
> Guacamole currently relies on approximating a value referred to as "processing lag" within
libguac, which represents the amount of additional time a connect used spends handling a frame
due to actual processing (image decoding, parsing the protocol, etc.). The idea here is to
keep the server and client in sync, while still allowing the server to send updates to the
client in an asynchronous manner. The client should stay offset from the server by a constant
amount of time which is roughly equal to network lag, and that lag should not continually
increase due to the server sending the client more data than it can process.
> This calculation works well, *except*:
> # The amount of time spent rendering the frame *on the server* is erroneously being taken
into account, effectively doubling the estimate of lag for non-trivial frames.
> # Bad timestamps sent from the client can result in the lag calculation overflowing into
negative values, which are ultimately interpreted as an enormous positive amount of lag ("the
user is 70 years behind - better wait for them to catch up!").
> The calculation should be modified such that server time is excluded, and bad timestamps
are not taken into account.

This message was sent by Atlassian JIRA

View raw message