Bug#934720: osm2pgsql 0.96 tile expiration memory leak

[j]

Package: osm2pgsql
Version: 0.92.0+ds-2
Severity: important
Tags: upstream

Dear Maintainer,

This bug report is for 0.96 from backports, NOT 0.92. To summarize, there appears to be a memory leak related to tile expiration. My initial bug report to the osm-dev list contains more information and can be found here (i'm afraid there are several relevant emails as my testing spanned several days):
https://lists.openstreetmap.org/pipermail/dev/2019-May/030644.html
https://lists.openstreetmap.org/pipermail/dev/2019-May/030645.html
https://lists.openstreetmap.org/pipermail/dev/2019-June/030680.html

Note: anywhere I mentioned '22GB', I should have said ~50GB as I did not initially take swap into account.

My workaround uses 0.92 output and an external program to emulate what the newer tile expiration code is supposed to do:
https://intergalacticdata.com/public_domain/expandExpire.c

At this time, we have chosen to regenerate our map periodically rather than expire tiles due to scale/cost of the required infrastructure. As such, I am unable to spend the time to create a clean patch.

Thanks for your time.

j

-- System Information:
Debian Release: 9.9
  APT prefers oldstable-updates
  APT policy: (500, 'oldstable-updates'), (500, 'oldstable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-9-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages osm2pgsql depends on:
ii  libboost-filesystem1.62.0  1.62.0+dfsg-4
ii  libboost-system1.62.0      1.62.0+dfsg-4
ii  libbz2-1.0                 1.0.6-8.1
ii  libc6                      2.24-11+deb9u4
ii  libexpat1                  2.2.0-2+deb9u2
ii  libgcc1                    1:6.3.0-18+deb9u1
ii  libgeos-3.5.1              3.5.1-3
ii  liblua5.2-0                5.2.4-1.1+b2
ii  libpq5                     11.4-1.pgdg90+1
ii  libproj12                  4.9.3-1
ii  libstdc++6                 6.3.0-18+deb9u1
ii  zlib1g                     1:1.2.8.dfsg-5

Versions of packages osm2pgsql recommends:
ii  postgis  2.5.2+dfsg-1~exp1.pgdg90+1

osm2pgsql suggests no packages.

-- no debconf information