Rudder

Thank you for your answer.
This configuration looks sane. Do you have a high load on the system? How many CPUs do you have?
Could you also send the logs (sanitized) from the webapp from the 5 minutes before the error ?

it may be that the ldap is overwhelmed, but i've never seen that with less than 5000 nodes

ok, so maybe that LDAP does not follow

Can you run this following script (from rudder-upgrade in 6.1)

  service rudder-jetty stop

  SLAPD_CONF="/opt/rudder/etc/openldap/slapd.conf" 
  NEED_REINDEX=false
  for i in "directiveId" "softwareVersion" "cn"; do
    line="index\s*${i}\s*eq" 
    INDEX_COUNT=$(grep -c "^${line}" ${SLAPD_CONF} 2>/dev/null || true)
    if [ ${INDEX_COUNT} -eq 0 ]; then
      echo "Adding LDAP index on attribute: ${i}" 
      sed -i "/index\s*objectClass\s*eq/a index\t${i}\teq" ${SLAPD_CONF}
      NEED_REINDEX=true
    fi
  done

  if ${NEED_REINDEX}; then
    # stop slapd, slapindex -q, start slapd. 
    systemctl stop rudder-slapd
    echo -n "Reindexing LDAP directory - this may take a few minutes..." 
    su - rudder-slapd -s /bin/sh -c "/opt/rudder/sbin/slapindex" 
    echo " Done" 
    systemctl start rudder-slapd
  fi

  service rudder-jetty start

it will add the ldap indexes that exists in 6.1, which does significantly improve perfs, notably concerning node inventory management (around 5 to 20 times faster)

We believe that these kind of bug (random error 500 with API) are all rooted to performance problems with LDAP.
We greatly improved our performance in that topic, and so I'm cloing that one. Please open again if you are still affected by it in recent rudder version.