mongodb - Unreadable terminal log from mongod 4.4 command

Question

I am using tmux as my default terminal.

The following is the terminal log, on entering the command sudo mongod

{"t":{"$date":"2021-01-28T18:10:29.521+05:30"},"s":"I",  "c":"CONTROL",  "id":23285,   "ctx":"main","msg":"Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'"}
{"t":{"$date":"2021-01-28T18:10:29.523+05:30"},"s":"W",  "c":"ASIO",     "id":22601,   "ctx":"main","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2021-01-28T18:10:29.523+05:30"},"s":"I",  "c":"NETWORK",  "id":4648601, "ctx":"main","msg":"Implicit TCP FastOpen unavailable. If TCP FastOpen is required, set tcpFastOpenServer, tcpFastOpenClient, and tcpFastOpenQueueSize."}
{"t":{"$date":"2021-01-28T18:10:29.524+05:30"},"s":"I",  "c":"STORAGE",  "id":4615611, "ctx":"initandlisten","msg":"MongoDB starting","attr":{"pid":27636,"port":27017,"dbPath":"/data/db","architecture":"64-bit","host":"khaldrogo-HP-Notebook"}}
{"t":{"$date":"2021-01-28T18:10:29.524+05:30"},"s":"I",  "c":"CONTROL",  "id":23403,   "ctx":"initandlisten","msg":"Build Info","attr":{"buildInfo":{"version":"4.4.3","gitVersion":"913d6b62acfbb344dde1b116f4161360acd8fd13","openSSLVersion":"OpenSSL 1.1.1f  31 Mar 2020","modules":[],"allocator":"tcmalloc","environment":{"distmod":"ubuntu2004","distarch":"x86_64","target_arch":"x86_64"}}}}
{"t":{"$date":"2021-01-28T18:10:29.524+05:30"},"s":"I",  "c":"CONTROL",  "id":51765,   "ctx":"initandlisten","msg":"Operating System","attr":{"os":{"name":"Ubuntu","version":"20.04"}}}
{"t":{"$date":"2021-01-28T18:10:29.524+05:30"},"s":"I",  "c":"CONTROL",  "id":21951,   "ctx":"initandlisten","msg":"Options set by command line","attr":{"options":{}}}
{"t":{"$date":"2021-01-28T18:10:29.547+05:30"},"s":"I",  "c":"STORAGE",  "id":22270,   "ctx":"initandlisten","msg":"Storage engine to use detected by data files","attr":{"dbpath":"/data/db","storageEngine":"wiredTiger"}}
{"t":{"$date":"2021-01-28T18:10:29.547+05:30"},"s":"I",  "c":"STORAGE",  "id":22297,   "ctx":"initandlisten","msg":"Using the XFS filesystem is strongly recommended with the WiredTiger storage engine. See http://dochub.mongodb.org/core/prodnotes-filesystem","tags":["startupWarnings"]}
{"t":{"$date":"2021-01-28T18:10:29.547+05:30"},"s":"I",  "c":"STORAGE",  "id":22315,   "ctx":"initandlisten","msg":"Opening WiredTiger","attr":{"config":"create,cache_size=1413M,session_max=33000,eviction=(threads_min=4,threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000,close_scan_interval=10,close_handle_minimum=250),statistics_log=(wait=0),verbose=[recovery_progress,checkpoint_progress,compact_progress],"}}
...continued

How do I get a proper format of output?

question from:https://stackoverflow.com/questions/65937402/unreadable-terminal-log-from-mongod-4-4-command

Answer 1

Mongo recommends jq tool.

This filter would generate output similar to the old style:

jq -c '.t["$date"] + " " + .s + " " + .c + " [" + .ctx + "] " + .msg' /var/log/mongo/mongo.log

It might be useful to filter only for warnings and errors:

select( .s == "W" or .s =="E" ) | .t["$date"] + " " + .s + " " + .c + " [" + .ctx + "] " + .msg

"2021-01-28T18:10:29.523+05:30 W ASIO [main] No TransportLayer configured during NetworkInterface startup"

or try this one:

select( .s | contains("W","E") ) | .t["$date"] + " -> " + .c + " " + .msg + "
   attr: " + (.attr | tostring) + "
   tags: " + (.tags|tostring)

See jq play