Problems with selectize inputs on 140-selectize-inputs example

[alandipert]

In testing, @shalutiwari and I have observed problems playing back recordings made against 140-selectize-inputs in rstudio/shiny-examples.

In particular, we see messages like this in the shinycannon output:

2019-11-22 00:35:28.670 WARN [thread01] - WS_RECV line 66: Haven't received message after 30 seconds

These messages indicate that the server has produced messages in a different order than anticipated by the recording, and shinycannon is stuck waiting for a message that will never come.

Since this problem only seems to manifest when selectize() inputs with server = TRUE is involved, our theory so far is that it has to do with server-side data processing latency. But we have yet to confirm that theory, or identify a fix.

[lachlansimpson]

Seen in customer ticket #91919