[Pkg-net-snmp-devel] Bug#975520: snmp: Performance refression for snmp commands since .index files removal

[florent.fourcot at wifirst.fr]

Package: snmp
Version: 5.7.3+dfsg-5+deb10u1
Severity: normal

Dear Maintainer,

Since last snmp release 5.7.3+dfsg-5+deb10u1, we detected performance
regressions on snmpget/walk/bulkwalk (probably all commands). We bisected
the regression to this patch:
https://github.com/net-snmp/net-snmp/commit/4fd9a450444a434a993bc72f7c3486ccce41f602

For snmpd daemon, performance impact is probably very slow, the .index file
was not mandatory. However, for our use case (monitoring application) running
a lot of snmp commands, strace show a big change on number of opened files:

grep -c openat snmpget_strace_before
55

And now:
grep -c openat snmpget_strace_new
2197

We are looking for workaround (or to accept this drawback), but if you have
a solution to restore this cache for snmp commands only (probably not
affected by security issues like snmpd), it would be greatly appreciated.

Best regards,

Florent Fourcot

-- System Information:
Debian Release: 10.4
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-6-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages snmp depends on:
ii  libc6         2.28-10
ii  libsnmp-base  5.7.3+dfsg-5+deb10u1
ii  libsnmp30     5.7.3+dfsg-5+deb10u1
ii  libssl1.1     1.1.1d-0+deb10u3

Versions of packages snmp recommends:
ii  perl  5.28.1-6

snmp suggests no packages.

-- no debconf information