Mongotail

Mongotail, Log all MongoDB queries in a "tail"able way.

mongotail is a command line tool to outputs any operation from a Mongo database in the standard output. You can see the operations collected by the database profiler from a console, or redirect the result to a file, pipes it with grep or other command line tool, etc.

The syntax is very similar to mongo client, and the output, as like tail command will be the latest 10 lines of logging.

But the more interesting feature (also like tail) is to see the changes in "real time" with the -f option, and occasionally filter the result with grep to find a particular operation.

MongoDB version 2.8 and above are supported.

Syntax

Usage:

mongotail [db address] [options]

"db address" can be:

New in 3.1: URIs with schemas mongodb:// and mongodb+srv:// are supported, e.g. mongodb://host:1234/foo, and user and password can also be set in the URI, although it's a very insecure way of provide that information. See bellow how to provide authentication information like user, password, auth database, ...

Optional arguments:

Enabling Database Profiling and Showing Logs

First you have to activate in the current database the profiler, so MongoDB will capture all the activity in a special collection that is read by Mongotail.

You can achieve this with the -l, --level option. For example, if you want to see the logs from MYDATABASE, first you have to execute:

$ mongotail MYDATABASE -l 2

Then you can see the latest logged records with:

$ mongotail MYDATABASE
2015-02-24 19:17:01.194 QUERY  [Company] : {"_id": ObjectId("548b164144ae122dc430376b")}. 1 returned.
2015-02-24 19:17:01.195 QUERY  [User] : {"_id": ObjectId("549048806b5d3db78cf6f654")}. 1 returned.
2015-02-24 19:17:01.196 UPDATE [Activation] : {"_id": "AB524"}, {"_id": "AB524", "code": "f2cbad0c"}. 1 updated.
2015-02-24 19:17:10.729 COUNT  [User] : {"active": {"$exists": true}, "firstName": {"$regex": "mac"}}
...

To Connect with SSL or a remote Mongo instance, check the options with mongotail --help.

Profiling considerations

NOTE: The level chosen can affect performance. It also can allow the server to write the content of queries to the log, which might have information security implications for your deployment. Remember to setup your database profiling level to 0 again after debugging your data:

$ mongotail MYDATABASE -l 0

Find slow queries

When you activate the profiler, you can choose to so with level 1 profiling instead of level 2. Level 1 configure the profiler system to log only "slow" operations. Then you have to set the threshold in milliseconds for the profile to consider an operation "slow". In the following example the threshold is set to 10 milliseconds:

$ mongotail sales -l 1
Profiling set to level 1
$ mongotail sales -s 10
Threshold profiling set to 10 milliseconds

Then when you check your databases only operations that take 10 or more milliseconds will be displayed.

A step-by-step guide of how to use Mongotail and the latest features is here.

Installation

See INSTALL.rst guide to install from sources. To install from PyPI repositories, follow these instructions depending of your OS:

Linux Installation

You can install the latest stable version with pip in your environment, but it's recommended to install it with Python 3 (pip3):

$ pip3 install mongotail

Execute this command with administrator/root privileges (in Debian/Ubuntu Linux distribution prepend sudo to the command).

You have to be installed pip / pip3 tool first. In Debian/Ubuntu Linux distribution you can install it with (also with root privileges):

$ apt-get install python3-pip

Install mongotail in the user space without root privileges is also possible with:

$ pip3 install --user mongotail

Note that the mongotail executable will be installed in the $HOME/.local/bin folder. If the folder didn't exist before, Pip will create it, but in the shell console the path won't be added to the $PATH variable until Bash is not instantiated again, so to be able to execute the command without the need to use the full path ($HOME/.local/bin/mongotail) just open a new Bash session.

Mac OSX Installation

First you need to install the Python package manager pip in your environment, and then like Linux to install Mongotail you can execute sudo pip install mongotail from the command line, but also it can be installed with easy_install, an old Python package manager present in most OSX versions. Try this:

$ sudo easy_install mongotail

Docker

Run with Docker (you don't need to download the source code):

$ docker run -it --rm mrsarm/mongotail --help

If you want to connect with a database also running locally in a container, you have to link both instances (see howto in the Docker documentation), or if the db is a local instance running without Docker, remember to use the local IP of your computer because the localhost address (IP 127.0.0.1) points to the container, not to your host. Eg.:

$ docker run -it --rm mrsarm/mongotail 192.168.0.21/test

If it does not work, it may be related with network access rules, or because the mongo instance is not listening remote connections, check to have properly configured the IP Binding.

About

Project: https://github.com/mrsarm/mongotail

Authors: (2015-2022) Mariano Ruiz <[email protected]>

Changelog: CHANGELOG.rst

More guides: http://mrsarm.blogspot.com.ar/search/label/Mongotail

License: GPL-3