ubuntu 18.04 awslogs Active: active (exited)

[EthanTang-Zq]

I use do-release-upgrade to upgrade Ubuntu16 to Ubuntu18. After awslogs cannot run, logs cannot be uploaded to aws cloudwatch.

Python 2.7.17

awslogs.service - LSB: Daemon for AWSLogs agent.
Loaded: loaded (/etc/init.d/awslogs; generated)
Active: active (exited) since Fri 2021-12-24 08:46:04 UTC; 16s ago
Docs: man:systemd-sysv-generator(8)
Process: 30691 ExecStop=/etc/init.d/awslogs stop (code=exited, status=0/SUCCESS)
Process: 30779 ExecStart=/etc/init.d/awslogs start (code=exited, status=0/SUCCESS)

Dec 24 08:46:04 ip- systemd[1]: Starting LSB: Daemon for AWSLogs agent....
Dec 24 08:46:04 ip- awslogs[30779]: Starting system awslogs daemon
Dec 24 08:46:04 ip- awslogs[30779]: * /var/awslogs/bin/awslogs-agent-launcher.sh is running
Dec 24 08:46:04 ip- systemd[1]: Started LSB: Daemon for AWSLogs agent..

/var/log/awslogs.log:
ImportError: cannot import name _remove_dead_weakref
Traceback (most recent call last):
File "/var/awslogs/bin/aws", line 19, in
import awscli.clidriver
File "/var/awslogs/local/lib/python2.7/site-packages/awscli/clidriver.py", line 15, in
import logging
File "/usr/lib/python2.7/logging/init.py", line 26, in
import sys, os, time, cStringIO, traceback, warnings, weakref, collections
File "/usr/lib/python2.7/weakref.py", line 14, in
from _weakref import (
ImportError: cannot import name _remove_dead_weakref