# hbtop ## Overview `hbtop` is a real-time monitoring tool for HBase like Unix's top command. It can display summary information as well as metrics per Region/Namespace/Table/RegionServer. In this tool, you can see the metrics sorted by a selected field and filter the metrics to see only metrics you really want to see. Also, with the drill-down feature, you can find hot regions easily in a top-down manner. ## Usage You can run hbtop with the following command: ``` $ hbase hbtop ``` In this case, the values of `hbase.client.zookeeper.quorum` and `zookeeper.znode.parent` in `hbase-site.xml` in the classpath or the default values of them are used to connect. Or, you can specify your own zookeeper quorum and znode parent as follows: ``` $ hbase hbtop -Dhbase.client.zookeeper.quorum= -Dzookeeper.znode.parent= ```  The top screen consists of a summary part and of a metrics part. In the summary part, you can see `HBase Version`, `Cluster ID`, `The number of region servers`, `Region count`, `Average Cluster Load` and `Aggregated Request/s`. In the metrics part, you can see metrics per Region/Namespace/Table/RegionServer depending on the selected mode. The top screen is refreshed in a certain period – 3 seconds by default. ### Scrolling metric records You can scroll the metric records in the metrics part.  ### Command line arguments | Argument | Description | |---|---| | -d,--delay <arg> | The refresh delay (in seconds); default is 3 seconds | | -h,--help | Print usage; for help while the tool is running press `h` key | | -m,--mode <arg> | The mode; `n` (Namespace)|`t` (Table)|r (Region)|`s` (RegionServer), default is `r` (Region) | ### Modes There are the following 4 modes in hbtop: | Mode | Description | |---|---| | Region | Showing metric records per region | | Namespace | Showing metric records per namespace | | Table | Showing metric records per table | | RegionServer | Showing metric records per region server | #### Region mode In Region mode, the default sort field is `#REQ/S`. The fields in this mode are as follows: | Field | Description | Displayed by default | |---|---|---| | RNAME | Region Name | false | | NAMESPACE | Namespace Name | true | | TABLE | Table Name | true | | SCODE | Start Code | false | | REPID | Replica ID | false | | REGION | Encoded Region Name | true | | RS | Short Region Server Name | true | | LRS | Long Region Server Name | false | | #REQ/S | Request Count per second | true | | #READ/S | Read Request Count per second | true | | #FREAD/S | Filtered Read Request Count per second | true | | #WRITE/S | Write Request Count per second | true | | SF | StoreFile Size | true | | USF | Uncompressed StoreFile Size | false | | #SF | Number of StoreFiles | true | | MEMSTORE | MemStore Size | true | | LOCALITY | Block Locality | true | | SKEY | Start Key | false | | #COMPingCELL | Compacting Cell Count | false | | #COMPedCELL | Compacted Cell Count | false | | %COMP | Compaction Progress | false | | LASTMCOMP | Last Major Compaction Time | false | #### Namespace mode In Namespace mode, the default sort field is `#REQ/S`. The fields in this mode are as follows: | Field | Description | Displayed by default | |---|---|---| | NAMESPACE | Namespace Name | true | | #REGION | Region Count | true | | #REQ/S | Request Count per second | true | | #READ/S | Read Request Count per second | true | | #FREAD/S | Filtered Read Request Count per second | true | | #WRITE/S | Write Request Count per second | true | | SF | StoreFile Size | true | | USF | Uncompressed StoreFile Size | false | | #SF | Number of StoreFiles | true | | MEMSTORE | MemStore Size | true | #### Table mode In Table mode, the default sort field is `#REQ/S`. The fields in this mode are as follows: | Field | Description | Displayed by default | |---|---|---| | NAMESPACE | Namespace Name | true | | TABLE | Table Name | true | | #REGION | Region Count | true | | #REQ/S | Request Count per second | true | | #READ/S | Read Request Count per second | true | | #FREAD/S | Filtered Read Request Count per second | true | | #WRITE/S | Write Request Count per second | true | | SF | StoreFile Size | true | | USF | Uncompressed StoreFile Size | false | | #SF | Number of StoreFiles | true | | MEMSTORE | MemStore Size | true | #### RegionServer mode In RegionServer mode, the default sort field is `#REQ/S`. The fields in this mode are as follows: | Field | Description | Displayed by default | |---|---|---| | RS | Short Region Server Name | true | | LRS | Long Region Server Name | false | | #REGION | Region Count | true | | #REQ/S | Request Count per second | true | | #READ/S | Read Request Count per second | true | | #FREAD/S | Filtered Read Request Count per second | true | | #WRITE/S | Write Request Count per second | true | | SF | StoreFile Size | true | | USF | Uncompressed StoreFile Size | false | | #SF | Number of StoreFiles | true | | MEMSTORE | MemStore Size | true | | UHEAP | Used Heap Size | true | | MHEAP | Max Heap Size | true | ### Changing mode You can change mode by pressing `m` key in the top screen.  ### Changing the refresh delay You can change the refresh by pressing `d` key in the top screen.  ### Changing the displayed fields You can move to the field screen by pressing `f` key in the top screen. In the fields screen, you can change the displayed fields by choosing a field and pressing `d` key or `space` key.  ### Changing the sort field You can move to the fields screen by pressing `f` key in the top screen. In the field screen, you can change the sort field by choosing a field and pressing `s`. Also, you can change the sort order (ascending or descending) by pressing `R` key.  ### Changing the order of the fields You can move to the fields screen by pressing `f` key in the top screen. In the field screen, you can change the order of the fields.  ### Filters You can filter the metric records with the filter feature. We can add filters by pressing `o` key for ignoring case or `O` key for case sensitive.  The syntax is as follows: ``` ``` For example, we can add filters like the following: ``` NAMESPACE==default REQ/S>1000 ``` The operators we can specify are as follows: | Operator | Description | |---|---| | = | Partial match | | == | Exact match | | > | Greater than | | >= | Greater than or equal to | | < | Less than | | <= | Less than and equal to | You can see the current filters by pressing `^o` key and clear them by pressing `=` key.  ### Drilling down You can drill down the metric record by choosing a metric record that you want to drill down and pressing `i` key in the top screen. With this feature, you can find hot regions easily in a top-down manner.  ### Help screen You can see the help screen by pressing `h` key in the top screen.  ## Others ### How hbtop gets the metrics data hbtop gets the metrics from ClusterMetrics which is returned as the result of a call to Admin#getClusterMetrics() on the current HMaster. To add metrics to hbtop, they will need to be exposed via ClusterMetrics.