# gcmon
*Ncurses console tool for monitoring Galera Cluster*

<img src="https://github.com/KrumBoychev/gcmon/raw/master/assets/gcmon.png"/>


## Overview
Galera Cluster Monitor - gcmon is console tool for centralized monitoring of Mysql Galera cluster nodes. The tool provides the same information as [myqstatus](https://github.com/jayjanssen/myq-tools) on a single screen/console.

## Install
``` bash
$ npm install gcmon
```


## Usage

 1. Configure the INSTALL_DIR/gcmon/etc/gcmon.json file:

	```json
	{
	        "thresholds": {
	                "fc_snt" : 10
	        },
	    "nodes":[
	        {"hostname" : "gdb1", "port":"3306", "user" : "user", "password": "secret"},
	        {"hostname" : "gdb2", "port":"3306", "user" : "user", "password": "secret"},
	        {"hostname" : "gdb3", "port":"3306", "user" : "user", "password": "secret"},
	        {"hostname" : "gdb4", "port":"3306", "user" : "user", "password": "secret"}
	    ]
	}
	```
	The thresholds configuration setting is used to monitor certain parameters and to highlight them on the screen
	if the threshold is reached. !!! Currently the only supported param is **fc_snt**!!!

	<img src="https://github.com/KrumBoychev/gcmon/raw/master/assets/gcmon02.png"/>


 2. Run the tool in debug mode to check if the communication with the nodes is OK:

	```
	$ ./gcmon -d  
	[18/03/2016 21:07:44.891] [INFO]  [gdb1] Connec
	[18/03/2016 21:07:44.970] [INFO]  [gdb2] Connect
	[18/03/2016 21:07:44.972] [INFO]  [gdb3] Connect
	[18/03/2016 21:07:44.973] [INFO]  [gdb4] Connect
	[18/03/2016 21:07:44.982] [INFO]  [gdb2] Connected as id 120
	[18/03/2016 21:07:44.989] [INFO]  [gdb3] Failed to connect!! Reason: Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'load'@'xxx.xxx.xxx.xxx' (using password: YES)
	[18/03/2016 21:07:44.991] [INFO]  [gdb4] Connected as id 779
	[18/03/2016 21:07:44.992] [INFO]  [gdb1] Connected as id 3903
	[18/03/2016 21:07:45.981] [INFO]  [gdb3] Node is not connected
	[18/03/2016 21:07:45.981] [INFO]  [gdb3] Reconnect
	[18/03/2016 21:07:46.010] [INFO]  [gdb2] Executing query 'show global status'
	[18/03/2016 21:07:46.011] [INFO]  [gdb2] Execute query return: 398 rows
	[18/03/2016 21:07:46.024] [INFO]  [gdb1] Executing query 'show global status'
	[18/03/2016 21:07:46.025] [INFO]  [gdb1] Execute query return: 398 rows
	[18/03/2016 21:07:46.033] [INFO]  [gdb4] Executing query 'show global status'
	[18/03/2016 21:07:46.034] [INFO]  [gdb4] Execute query return: 398 rows
	[18/03/2016 21:07:46.038] [INFO]  [gdb3] Failed to connect!! Reason: Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'load'@'xxx.xxx.xxx.xxx' (using password: YES)

	```

 3. After the connection verification, run the tool in ncurses mode:
	
	
		**NOTE!!!**
	
	>  Many SSH emulators like **Putty** will use UTF-8 mode. This in turn
	> will result in the session not use the correct character set.  Ncurses
	> attempts to use the "graphical" character set for drawing lines. Which
	> results in alpha and numeric characters when executing the ncurses
	> environment. One of the possible solutions is to export
	> **NCURSES_NO_UTF8_ACS=1** to your .bashrc.
	[putty-utf8-and-ncurses](https://thesorcerer.wordpress.com/2015/04/01/how-to-solve-some-graphical-issues-with-putty-utf8-and-ncurses/)
	
	```
	 $ ./gcmon
	```
    
	<img src="https://github.com/KrumBoychev/gcmon/raw/master/assets/gcmon03.png"/>

 4. To exit from the application use **q**
	
 5. For additional options check the help:
	```
	$ ./gcmon -h
	
		Description
	
		  gcmon(v1.0.0) -Galera Cluster Monitor  
	
		Synopsis
	
		  $ gcmon --help
		  $ gcmon [--config file]
		  $ gcmon [--interval seconds] --debug
	
		Options
	
		  -h, --help                 Display this usage guide.
		  -v, --version              Version                   
		  -d, --debug                Debug communication.      
		  -i, --interval <seconds>   Collect data interval.    
		  -c, --config <file>        Config file.
```