Health Check Configuration

Health Check Configuration

Most configurations has default and works out of the box. Unless you want to customize the tool, you can skip this section.

There is a build-in config.json so you don't need to write your own configuration.

You can pass your own configuration to the tool by specifying -c or --config.

This is a example of config file /config.json.

{
    "checksets":{
        "default": {
            "items": ["ClusterItem", "ServerStatusItem", "ShardKeyItem","HostInfoItem", "BuildInfoItem", "SecurityItem", "CollInfoItem", "IndexInfoItem"]
        }
    },
    "item_config": {
        "BuildInfoItem": {
            "eol_version": [4, 4, 0]
        },
        "CollInfoItem": {
            "obj_size_kb": 32,
            "collection_size_gb": 2048,
            "fragmentation_ratio": 0.5,
            "index_size_ratio": 0.2,
            "ops_latency_ms": 100
        },
        "IndexInfoItem": {
            "unused_index_days": 7,
            "num_indexes": 10
        },
        "ClusterItem": {
            "replication_lag_seconds": 0,
            "oplog_window_hours": 48
        },
        "ServerStatusItem": {
            "used_connection_ratio": 0.8,
            "query_targeting": 1000,
            "query_targeting_obj": 1000,
            "cache_read_into_mb": 100
        },
        "ShardKeyItem": {
            "sharding_imbalance_percentage": 0.1
        }
    },
    "template": "standard.html"
}

There's also the /config_test.json which sets the thresholds to a very low value. It will fail most tests and is mainly used for testing purpose.

1 Checksets

The checksets section in the above example.
Check sets allows you to define a group of check items that you want to run against the database. By default there's default checkset, which enables all check items. You can define new checksets that include different items. And you can choose which checkset to run by passing the -s or --checkset with the set name.

To define a checkset, add a new key in the checksets section:

• checksets.<your set name>.items: Array of strings. The names of check items.

2 Item Config

The item_config section in the above example.
Each check item uses some thresholds to help determine whether a value is in the reasonable range. Some items don't need any thresholds like the SecurityItem. Exceeding any threshold will record a test fail item in the final report.

Item Name	Value	Meaning	Default
BuildInfoItem	eol_version	Version older than this setting will be considered end of life.	[4, 4, 0]
CollInfoItem	obj_size_kb	Largest object size in KB.	32
CollInfoItem	collection_size_GB	Largest collection size in GB.	2048
CollInfoItem	fragmentation_ratio	Highest storage fragmentation ratio.	0.5
CollInfoItem	index_size_ratio	Largest index:storage ratio.	0.2
CollInfoItem	ops_latency_ms	Highest operation latency in ms.	100
IndexInfoItem	unused_index_days	Longest unused days.	7
IndexInfoItem	num_indexes	Number of indexes on one collection.	10
ClusterItem	replication_lag_seconds	Replication lag in seconds.	0
ClusterItem	oplog_window_hours	Oplog window in hours.	48
ServerStatusItem	used_connection_ratio	Highest used:total connection ratio	0.8
ServerStatusItem	query_targeting	Scanned:Returned	1000
ServerStatusItem	query_targeting_obj	Scanned Object:Returned	1000
ServerStatusItem	cache_read_into_mb	Data read into cache / s	100