Chapter 3 Performance Pages

Table of Contents

3.1 Connections
3.2 Statements
3.3 InnoDB Buffer Pool
3.4 InnoDB File I/O
3.5 Tables / Rows
3.6 Query Cache

The Performance pages are available from the Performance sub-menu of the MySQL Database menu. These pages display specific aspects of your MySQL performance.

The following Performance pages are available:

Each of the performance pages graphs the performance of a specific metric, or set of metrics, over a 24-hour window. They also display configuration information.

Each graph region also contains links to week and month overviews of the collected data. Click the appropriate link to display the week or month graph.

Each metric is graphed with a separate line. Each point on the line represents the data collected according to the defined Collection Schedule. If the Collection Schedule is defined as 5 minutes, each point on the graph is separated by 5 minutes.

To see data on each individual collection point, hover the cursor over the line. A tooltip is displayed listing the data type, the time the data was collected, and the value of the metric collected.

3.1 Connections

The Connections page displays the connections and network statistics for the monitored MySQL instance.

Table 3.1 Connections Performance Page Regions

GraphDescription
Current ConnectionsGraphs the number of current, running and cached connections.
Total ConnectionsGraphs the total number of connection attempts, successful or not, to the monitored instance.
Network UsageGraphs the network usage in bytes sent and received.
Slowly Launched ThreadsGraphs the slow launched threads.
Connections AbortedGraphs the number of aborted clients and connections per collection.
Max UsedGraphs the maximum number of connections in use simultaneously since the monitored instance started.
Connection ConfigurationLists the connection-specific system variables and their values.
Thread ConfigurationLists the thread-specific system variables and their values.


3.2 Statements

Table 3.2 Statements Performance Page Regions

GraphDescription
DML StatementsGraphs the number and type of DML statements. The following statement types are graphed: SELECT, INSERT, UPDATE, REPLACE, DELETE and Call Procedures.
Transaction StatementsGraphs the number and type of Transaction statements. The following transaction statements are graphed: BEGIN, COMMIT, ROLLBACK, SAVEPOINT, ROLLBACK TO SAVEPOINT and RELEASE SAVEPOINT.
Row ActivityGraphs the type of row activity and the number of rows acted upon.
Index Usage RatioGraphs the change in rows read by indexes versus rows read by table scans.
Temporary TablesGraphs the number of temporary tables created in the database and on disk.
Sort ActivityGraphs the number of sort merge passes, the number of sorts done using ranges, and the number of sorts performed by scanning tables.
Statement ConfigurationLists the statement-specific system variables and their values.
Optimizer ConfigurationLists the optimizer-specific system variables and their values.


3.3 InnoDB Buffer Pool

Table 3.3 InnoDB Buffer Pool Performance Page Regions

GraphDescription
Buffer UsageGraphs the amount of megabytes in the InnoDB buffer pool which contain data and the number of megabytes held in dirty pages.
Row RequestsGraphs the number of logical read requests, logical read requests read from disk, and writes done to the buffer pool.
Page ActivityGraphs the number of buffer pool pages read, written and created.
Waits for Free PagesGraphs the number of times writes to the buffer pool waited for clean pages to become available.
Pages FlushedGraphs the number of buffer pool page-flush requests.
Pages LatchedGraphs the number of buffer pool pages latched.
Young Page ActivityGraphs the number of pages made young and not young in the LRU list.
Pending OperationsGraphs the number of pending reads, LRU writes, single-page writes and pages to be flushed during checkpointing.
Page Read AheadGraphs the number of pages reads into the buffer pool by the read ahead thread and the number of pages evicted.
Compression TimeGraphs the time, in seconds, spent compressing or uncompressing buffer pool pages.
Current UsagePie chart which displays how the buffer pool is currently used.
InnoDB Buffer ConfigurationLists the buffer-pool-specific system variables and their values.


3.4 InnoDB File I/O

Table 3.4 InnoDB File I/O Performance Page Regions

NameDescription
Data File IO Activity (bytes)Graphs the amount of data read and written, in bytes.
Data File IO Activity (ops)Graphs the number of fsync() operations, data reads and writes.
Average Bytes Per ReadGraphs the average bytes per read.
Double Write ActivityGraphs the number of doublewrite operations and the number of pages written for doublewrite operations.
Redo Log IO Activity (bytes)Graphs the number of bytes written to the log file.
Redo Log IO Activity (ops)Graphs the number of log write requests and the number of physical log writes.
Redo Log WaitsGraphs the number of times the log buffer was too small and had to be flushed.
Pending IOGraphs the number of pending asynchronous I/O read/write requests,
Pending FlushesGraphs the number of pending buffer and redo log flush operations.
Open FilesGraphs the number of open files in InnoDB.
InnoDB IO ConfigurationLists the InnoDB IO-specific system variables and their values.


3.5 Tables / Rows

Table 3.5 Tables / Rows Performance Page Regions

NameDescription
Opened TablesGraphs the number of cached frm files and the total number of opened tables.
Currently Open TablesGraphs the number of tables open in the table cache.
Temporary TablesGraphs the number of temporary tables created, and the number of temporary tables converted to disk-based tables.
Table LocksGraphs the number of times a table lock request was granted immediately and the number of times it could not be granted immediately.
Table Scan RatioGraphs the ratio of rows read via indexes versus rows read via table scan.
Row ReadsGraphs the average of rows read via indexes per second and the rows read via scan.
Row WritesGraphs the number of requests to write, update or delete a row.
SortsGraphs the number of sorts performed using ranges and scans.
Rows SortedGraphs the number of sorted rows.
Sort Merge PassesGraphs the number of merge passes performed by the sort algorithm.
Table ConfigurationLists the table-specific system variables and their values.


3.6 Query Cache

Table 3.6 Query Cache Performance Page Regions

NameDescription
EfficiencyGraphs the number of Query Cache hits, inserts and non-cached queries.
Queries in CacheGraphs the number of queries registered in the Query Cache.
Free Memory (MB)Graphs the amount of free memory allocated to the Query Cache.
Average Free Block Size (KB)Graphs the average size, in kilobytes, of the free blocks within the Query Cache.
Low Memory PrunesGraphs the number of queries deleted from the Query Cache due to low memory.
FragmentationGraphs the number of free blocks in the Query Cache.
Query Cache ConfigurationLists the Query Cache-specific system variables and their values.