delays in loading history data cause all other pages to malfunction

[dd1]

If there is a delay loading more history data, all other pages malfunction. This is caused by google-chrome multiplexing all requests across one or two tcp connections. If this tcp connection stalls while waiting for more history data, all other web requests stall, too. There are no good solutions for this. Maybe change how history pages to load the data in smaller chunks. Maybe start using http/3 (not yet supported by apache httpd). K.O.

[dd1]

test URLs from bug 286 hit this problem. there is a 1 minute timeout from the apache https proxy (the best I can tell). after the timeout, whatever was stuck behind the history-read RPC (load of css, svg icons, etc) also fails to load. google chrome reports status 500 for the whole bunch. K.O.

[dd1]

issue is “http head of line blocking”. everybody has to wait for the history-read RPC to complete. web browser will not open additional tcp socket to bypass “stuck” RPC request. bummer.

two solutions:

• try http/2 - seems to be available in ubuntu-20
• have history-read RPC quickly return “data is not ready yet”. the web page will have to “poll” mhttpd until history read completes (on a separate thread, I guess) and history data can be returned.

my test machine agmini is CentOS-7, no http/2 there. cannot test. bummer.

K.O.