First of all, i would recommend to upgrade to NaviServer 4.99.20, since there are many changes in the code, also affecting low-level I/O, connchan handling, etc. This will be much more robust also in connection with partial reads/writes and addresses changes in the behavior of newer versions of OpenSSL.
Anyhow, what i can read from your lines above is the following:
- setting "-timeout 10"
- start of request "29/Jan/2021:22:42:49"
- timeout" 29/Jan/2021:22:42:59" while spooling from conn7 to conn6
Well, between (2) and (3) there are 10 seconds, the timeout value. Since it spools some data to conn6, i would assume that conn6 is the client (browser) and conn7 is the backend (node) . Since there is no reply from conn7 within this time span, the timeout occurs.
One question is, what happens on the node side? Maybe there are some entries in the log-file?
You can intensify the logging by turning on more log levels on the NaviServer side, especially on connchan. When you add for example the following line to the begin of the revproxy-procs, then you get more detailed information (be careful, if this is a busy site, you might get too much). One can certainly turn more detailed logging dynamically (maybe per revproxy PUT requests, but you have to add activation/deactivation yourself to the proc).
ns_logctl severity Debug(connchan) on
