[Bug]: Reactor memory leak

[xsmile]

What happened?

A memory leak in the reactor is present since 3006.16, introduced in salt/transport/zeromq.py with commit 145a06e .

Running salt-master via the memory profiler memray while triggering reactor events for 20 minutes shows the following memory usage graphs for the reactor process.

A workaround is to revert the file to 3006.15 (or 3006.14 due to the lower memory usage).

3006.16

3006.15

3006.14

Type of salt install

Official deb

Major version

3006.x

What supported OS are you seeing the problem on? Can select multiple. (If bug appears on an unsupported OS, please open a GitHub Discussion instead)

ubuntu-24.04

salt --versions-report output

Salt Version:
          Salt: 3006.19

Python Version:
        Python: 3.10.19 (main, Jan  7 2026, 23:50:47) [GCC 11.2.0]

Dependency Versions:
          cffi: 2.0.0
      cherrypy: 18.10.0
  cryptography: 42.0.5
      dateutil: 2.8.1
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 3.1.6
       libgit2: Not Installed
  looseversion: 1.0.2
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 24.0
     pycparser: 2.21
      pycrypto: Not Installed
  pycryptodome: 3.19.1
        pygit2: Not Installed
  python-gnupg: 0.4.8
        PyYAML: 6.0.1
         PyZMQ: 23.2.0
        relenv: 0.22.2
         smmap: Not Installed
       timelib: 0.3.0
       Tornado: 4.5.3
           ZMQ: 4.3.4

System Versions:
          dist: ubuntu 24.04.2 noble
        locale: utf-8
       machine: x86_64
       release: 6.8.0-90-generic
        system: Linux
       version: Ubuntu 24.04.2 noble