Server Metrics

The Server Metrics dashboard is accessible by selecting relevant data in the MySQL Server Overview. When you open the Server Metrics dashboard from the MySQL Server Overview, the tab will automatically show the category of the selected component.

This section describes the following key areas:

• Server Metrics Health Overview
• Server Metrics Categories
  • Connection Status
  • Handler
  • Innodb Buffer Pool
  • Innodb Compression
  • Innodb Storage Engine
  • InnoDB Transaction Log
  • Joins
  • Key Buffer
  • Network Interface
  • Query Cache
  • Sort Buffer
  • Thread Pool

Server Metrics Health Overview

The Server Metrics dashboard displays overview boxes that show the current health state and all active alarms for each component of the agent’s data collection. Clicking or hovering over the health icon or outstanding alarms will bring up additional information related to the state of that component.

The following are detailed descriptions of the metrics in individual categories:

Server Metrics Categories

Connection Status

• Max Used Connections - The maximum number of connections that have been in use simultaneously since the server started.
• Connection Info - The number of connection attempts (successful or not) to the MySQL server.
• Connectivity % - The probability of making a successful new connection.
• Connection Length – The number of seconds MySQL took to establish a new connection.

Handler

• Good Key Reads – Number of reads employing table keys, usually indicative of good indexing.
• Bad Indexing Reads – Number of reads which typically indicate bad indexing.
• Modify Requests – Requests related to modifying table data through writing, updating, or deleting rows.
• Commit Info – MySQL metrics related to transaction commits.
• Rollback Info - MySQL metrics related to transaction rollbacks.

Innodb Buffer Pool

• Hit/Miss Rate – Hit and Miss rate percentages for InnoDB Buffer Pool.
• Memory Allocation – Amount of memory allocated to the InnoDB Buffer Pool and Log Buffer Size.
• Buffer Pool Pages – Breakdown of Buffer Pages by type.
• Modified Pages – Number of Buffer Pages being modified.

Innodb Compression

• Properties - InnoDB compression-related variables
• Compression by Mem Page Size – Compression metrics grouped by memory page size.
• Compression by Page Size – Compression metrics grouped by page size.

Innodb Storage Engine

• Queries in Queue – The number of queries waiting to enter InnoDB.
• Queries inside InnoDB – The number of queries active inside InnoDB.
• Rows Affected by Query Type – The amount of rows per second which are being affected, shown according to the type of query affecting them.
• Data Reads/Writes – The number of physical data reads and writes per second.
• Insert Buffer Async I/O – The number of insert buffer asynchronous I/O reads and writes per second.
• Pending Normal Async I/O – The number of pending normal asynchronous I/O reads and writes per second.
• Mutex Info – Information relating to InnoDB waiting for a mutex.
• RW Locks – Information relating to InnoDB waiting for a read/write lock to be released.
• OS File I/O – The rate of Operating System reads, writes, and fsync operations per second.
• Transactions Rate – The InnoDB transaction rate graphed over time.
• Transaction Purge Lag – The transaction purge lag graphed over time.

InnoDB Transaction Log

• Unflushed Percent – The percent of InnoDB log buffer that has yet to be flushed to disk.
• Transaction Log Data Performance – The rate of writes and waits for the Transaction Log to be flushed to disk.

Joins

• First Table Search Joins – The number of joins operating on the first table.
• Bad Joins – Inefficient joins which do not use keys or indexes.
• Full Range Joins – The number of joins that used a range search on a reference table.

Key Buffer

• Key Reads – The number of reads or read requests for a key block.
• Key Writes – The number of write or write requests for a key block.
• Key Hit Rate – The rate of physical reads from a disk to requests to read from the cache.
• Key Blocks – A status breakdown of key blocks in the key caches.

Network Interface

• Byte Transfer Rates - The number of bytes received and sent per second from and to the network

Query Cache

• Cache Memory Usage – A breakdown of the total cache size into free and used memory.
• Cache Memory Blocks – A breakdown of the total cache blocks into free and used blocks.
• Hit Rate % - The percent of SQL queries used from the Query Cache.
• Statements Executed – The number of SQL statements currently being executed.
• Statement Execution Rate – The number of SQL statements per second that are currently being executed.
• Cache I/O Activity – The number of statements being added to the cache, existing in the cache, and being dropped from the cache.
• Queries Not Cached – The number of non-cached queries.

Sort Buffer

• Sort Buffer Size – The buffer size that each thread needs to allocate to do a sort.
• Row Sort Rate – The number of rows being sorted per second.
• Sorting Rates – The sorting rates per second broken down by type of sort.

Thread Pool

• Hit Rate Percent – The number of threads that were used from the pool in comparison to the total number of connections made.
• Threads Created Rate – The number of new threads created per second.
• Thread Pool Cache – The number of threads in the Thread Pool and currently open connections.
• Active Threads – The number of currently open connections and active threads.