MySQL Enterprise Monitor Glossary

These terms are commonly used in information about the MySQL Enterprise Monitor product.



A rule and the alarms and notifications associated with it. Sets of advisors that perform related measurements are grouped together into collections. Advisors are a crucial aspect of the monitoring system. The MySQL Enterprise Monitor product comes with a number of standard advisors. Based on your organization's particular needs, you may create or adapt custom advisors.

See Also Advisors tab, alarm, collection, custom, notification, rule, schedule, standard.

advisor group

A collection of similar advisors shown on the Advisors tab. For example, there are predefined advisor groups such as Administration, Cluster, and Heat Chart.

See Also advisor, Advisors tab.

Advisors tab

A page within the UI where you can manage advisors, both standard and custom ones. See Section 2.3, “The Advisors Tab”.

See Also advisor, custom, Dashboard, standard.


The MySQL Enterprise Monitor component that actively collects data from MySQL server instances. The data is transmitted to the Service Manager. The Agent includes an optional subcomponent, the Aggregator, which can intercept query data as it passes between applications and the database, and again transmit that data to the Service Manager.

See Also instance, Service Manager.


An optional subcomponent of the Agent. It can intercept query data as it passes between applications and the database, and transmit that data to the Service Manager. To collect query data from applications requires using a MySQL Enterprise Plugin for the appropriate Connector based on the application language or framework.

See Also Agent, Connector, plugin, Service Manager.


The persistent record of an event, including its severity: critical, warning, or informational. Alarms are displayed in the Heat Chart and on the Events tab. Serious alarms produce notifications.

See Also alert, Critical, event, Informational, notification, Warning.


A kind of notification caused by rule evaluation within an advisor. Displayed on the Events tab.

See Also advisor, alarm, event, Events tab, notification, SMTP, Warning.


The web server that runs the Tomcat servlet container that powers the UI. The MySQL Enterprise Monitor Service Manager installation includes the Apache web server.

See Also Dashboard, Service Manager, Tomcat.


A component that the MySQL Enterprise Monitor product monitors, such as a MySQL server instance, or a CPU or file system within a server machine. Contrast with metric, which is a property within the component that is measured.

See Also instance, metric.

Asset Selector

The Groups shown in the Asset Selector are the ones you create and manage (on the MySQL Instances Dashboard, or during Agent installation) and those that are discovered automatically from monitoring replication topologies. It is on the left side of many UI pages that controls content in the main-body of the page.

See Also asset, Dashboard, graph.


The mechanism that detects the set of master, slave, and master/slave servers in a replication configuration, and displays the topology in the Server tree.

See Also Asset Selector, master, replication, Server tree, slave, topology.


best practice

Within the MySQL Enterprise Monitor product, a best practice is a specific rule backed up by a metric. When a threshold value is reached, the Service Manager raises an alarm.

See Also alarm, metric, rule, Service Manager, threshold.

blackout period

A time period where an Agent stops reporting information from a MySQL server instance. Typically, this is during a maintenance period when the database might go through an unusual workload that does not require raising any alarms.

See Also Agent, instance, notification.


An aspect or component of a system whose capacity imposes a limit on performance. In MySQL Enterprise Monitor, you identify bottlenecks in areas such as I/O or memory usage using graphs, and use advisors to automatically raise alerts when problems occur.

See Also advisor, alert, graph.


The bundled MySQL server refers to the MySQL server that can be installed along with the MySQL Enterprise Monitor product, to serve as the repository for the collected data.

See Also repository.



The C programming language.

canonical query

A synonym for normalized query.

See Also normalized query.

chain replication

In replication, a kind of topology where each server acts as a master/slave server, connected to at most two other servers.

See Also circular replication, master/slave, replication, topology.

circular replication

In a replication configuration, a topology where every server is both a master and a slave, connected to two other servers, forming a ring structure. Forms a ring structure.

See Also replication, ring replication, topology.


A set of related advisors.

See Also advisor.


A software component (analogous to a driver) that provide connectivity to the MySQL server for client programs. MySQL comes with connectors for several programming languages and frameworks. The MySQL Enterprise Monitor product includes plugins for certain collectors, to help monitor queries sent by application programs and use that data within the Query Analyzer.

See Also Connector/J, Connector/Net, Connector/PHP, query, Query Analyzer.


The Connector for applications written in the Java programming language. It communicates directly with the MySQL server without going through the libmysqlclient shared library.

See Also Connector, Java.


The Connector for applications written with the .NET programming framework. It communicates directly with the MySQL server without going through the libmysqlclient shared library.

See Also .NET, Connector.


The Connector for applications written in the PHP programming language. The mechanism for communicating with the MySQL server may differ depending on the version of PHP involved.

See Also Connector, PHP.


The MySQL Enterprise Monitor product interfaces with many different databases and other kinds of servers. Each of these components can have its own login and security credentials. MySQL Enterprise Monitor pulls performance data from the MySQL servers that you monitor, stores the resulting data in a repository that is also a MySQL server, and sends alerts by communicating through other kinds of servers such as SMTP for e-mail alerts and NMS for SNMP traps. It pulls support-related data from the My Oracle Support site. You view the results in the UI, which is protected by its own login and optionally by LDAP authentication.

See Also Dashboard, LDAP, NMS, repository, SMTP, SNMP.


A high severity level for alarms. Within a rule, you can designate the threshold values that specify whether an alarm triggers a Critical, Warning, or Informational alert.

See Also advisor, alarm, event, Informational, rule, threshold, Warning.


User-created rules and graphs. Contrast with standard.

See Also graph, rule, standard.



The MySQL Enterprise Dashboard is a web-based interface to the MySQL Enterprise Service Manager. The user interface consists of a series of tab pages. The back end is a Java application powered by the Tomcat server.

See Also Advisors tab, Events tab, Graphs tab, Monitor tab, Query Analyzer tab, Replication tab, Service Manager, Settings tab, Tomcat, What's New tab.

data collection item

Data values derived from server status variables, operating system status information, and MySQL table information. You can reference these items using mnemonic names in expressions when you create or edit rules.

See Also expression, rule.



A slightly more comprehensive synonym for alarm Evaluating a rule generates an event. The result of an event can be success if everything is OK. An alarm is raised only if something goes wrong. You monitor events using the Events tab.

See Also alarm, alert, Critical, Events tab, Informational, notification, Warning.

Events tab

A page within the UI, for monitoring events. See Section 2.4, “The Events Tab”.

See Also Dashboard, event.


A textual report showing the internal mechanisms used by a query, and estimates for the cost, such as amount of data to process, involved in each step. Performance monitoring involves checking whether queries that are slow or frequently run could be sped up or made less resource-intensive, by examining the EXPLAIN plan to check if the MySQL optimizer has chosen the most efficient ways to process indexes, order join clauses, and so on. The MySQL Enterprise Monitor product includes a number of features for visualizing EXPLAIN plans. These features are language-dependent, relying on support in the various Connectors for programming languages and frameworks.

See Also query.


The part of a rule that tests a metric against a threshold value.

See Also alarm, metric, rule, threshold.



Additional considerations apply when the server you are monitoring is separated from the Service Manager by a firewall.

See Also remote, Service Manager, SSL.

full table scan

An aspect of a SELECT query that often indicates a performance or scalability issue. The query scans every row in a table, rather than using an index to look up a subset of rows. It can be a non-issue for small tables that are cached in memory. It can be unavoidable when querying large tables to prepare reports. Performance issues are most likely when the table being scanned is involved in a join operation, when the query is run frequently, or when the result set only references a small fraction of the rows in the table.

To diagnose possible issues due to full table scans, choose a time period of heavy SQL activity from one of the graphs, use the Query Analyzer to locate queries that process large numbers of rows, and examine the explain plan for the queries. The notation in the explain plan that indicates a full table scan is Type=ALL.

See Also EXPLAIN plan, graph, query, Query Analyzer.



A visual representation of server activity, resources, or other metrics over time. You monitor graphs using the Graphs tab.

See Also Graphs tab, Heat Chart, metric.

Graphs tab

A page within the Dashboard that displays graphs of server activity and resources. See Section 2.5, “The Graphs Tab”.

See Also Dashboard, graph.



A periodic signal sent from each agent to the Service Manager, so that the Service Manager can verify that the agents are still running and able to connect. You typically use URLs containing heartbeat to verify a network connection between machines running different MySQL Enterprise Monitor components.

See Also Agent, Service Manager.

Heat Chart

A special chart that shows the status of critical rules. These rules are grouped together as an advisor, known as the Heat Chart Advisor. It can be displayed as part of the Dashboard or remain permanently open in its own window. See Section 2.2.2, “The Heat Chart”.

See Also advisor, Dashboard.


A computer running one or more instances of MySQL server.

See Also instance, MySQL server.



A low severity level for alarms. Within a rule, you can designate the threshold values that specify the severity level that is triggered.

See Also advisor, Critical, event, rule, threshold, Warning.


A mysqld daemon running on a MySQL server. There might be multiple instances running on the same server machine. An instance is one of the kinds of asset that the MySQL Enterprise Monitor product can monitor.

See Also asset.


A persisted instance of a run-time metric evaluation. These may store the raw metric data, or the result of an expression or function against a metric. Instruments are generally stored for things that will show in the GUI, such as graph data.

See Also graph, metric.


Core information about a host or MySQL server instance. This data is collected by the Agent. The inventory includes details such as the MySQL server version number, supported storage engines and replication configuration. The data in the inventory helps to determine what other kinds of data can be collected from the hosts and MySQL servers.

See Also Agent, instance, replication.



The MySQL Enterprise Plugin for Connector/J enables any application using the Connector/J JDBC driver to supply query analyzer information directly to MySQL Enterprise Service Manager. Information is sent to the MySQL Enterprise Service Manager for analysis without any need to modify your applications.

The MySQL Enterprise Monitor product is also partly built on Java technology, using the Tomcat servlet container for the web-based GUI. It uses a JVM on the machine that runs the Service Manager, its performance is affected by the Tomcat configuration parameters, and during troubleshooting you might use diagnostic information from the Java environment.

See Also Connector/J, Dashboard, JDBC, plugin, Query Analyzer, Tomcat.


The underlying database API used by many Java applications, including the Connector/J component.

See Also Connector/J, Java.



An authentication mechanism that can control access to the UI. On Linux, Unix, and OS X systems, you might have a separate LDAP server where each user has their own credentials. On Windows systems, the LDAP protocol is used to connect to an Active Directory server for the same authentication purposes. Typically, you map LDAP roles to corresponding MySQL Enterprise Monitor roles, to enable groups of users to have basic or administrative access to the Dashboard without configuring each user individually, or giving them a new user ID and password, or requiring extra work to revoke access when they leave the organization.

See Also credentials, Dashboard, role.

log file

The MySQL Enterprise Monitor product manages log files for the Tomcat, repository, and Service Manager components, as well as a configuration report pertaining to the initial installation. You can view each of these configuration files through the UI, or by examining the physical file.

See Also Dashboard, repository, Service Manager, Tomcat.


A programming language that is used for parts of the Agent, Aggregator, Service Manager, and Query Analyzer components. Although you do not need to know this language to operate the MySQL Enterprise Monitor product, sometimes you specify options containing file paths related to Lua scripts or libraries.

See Also Agent, Aggregator, Query Analyzer, Service Manager.



In a replication configuration, a database server that sends updates to a set of slave servers. It typically dedicates most of its resources to write operations, leaving user queries to the slaves. In complex topologies, a server can be both a master and a slave, known as a master/slave.

See Also master/slave, replication, slave, topology.


In replication, a server that acts as a slave to receive updates from another server, and also acts as a master to propagate changes to another set of slave servers. Keeps the top-level master from having to service too many slaves, and allows certain kinds of changes to be propagated to a subset of slaves. This topology is represented as a tree, with all the intermediate nodes being master/slave servers.

See Also master, replication, slave, topology, tree.


Any property that is measured using a numeric value. Within MySQL Enterprise Monitor, such measurements can be displayed over time as a graph, or an alert can be sent when a threshold value is reached. Each metric is collected from an asset. For example, how much time is taken by a database query, or how full is the file system on a server machine.

See Also alert, asset, graph, threshold.

mixed replication

In a replication configuration, a kind of topology consisting of different combinations of master, slave, and dual-purpose master/slave servers.

See Also chain replication, circular replication, master, master/slave, replication, slave, topology, tree.


To view information about the state, health, activity, and history of a resource such as a MySQL server instance. Monitoring can help to diagnose problems, spot worrisome trends before they turn into problems, reassure when systems are operating normally, and notify when an operator needs to take corrective action. With MySQL Enterprise Monitor, the component you interact with during monitoring is the UI.

See Also Dashboard, instance.

Monitor tab

A page within the UI that provides a quick overview of your current monitoring information. It can serve as an instant health check for all the MySQL servers across the enterprise.

See Also Dashboard.

My Oracle Support

The web site for filing bugs and service requests with Oracle Support. (Commercial customers such as MySQL Enterprise Monitor users now use the official Oracle support channel rather than the MySQL bug database.) In MySQL Enterprise Monitor, you interact with the support site through the What's New tab.

See Also service request, What's New tab.

MySQL server

The MySQL database instance running on a host computer. More than one MySQL instance can run on the same computer, either as separate mysqld processes or through virtualization.

See Also instance.



A programming framework used by many Windows applications, including the Connector/Net component.

See Also Connector/Net.


Acronym for Network Management System, a type of monitoring system that is separate from the MySQL Enterprise Monitor product. If your network has this kind of monitoring capability, MySQL Enterprise Monitor can notify the NMS of network issues by translating events into SNMP traps.

See Also event, SNMP.

normalized query

A condensed form of the query text used to treat similar queries as if they were identical, for monitoring performance. When MySQL Enterprise Monitor normalizes queries, it disregards differences in keyword capitalization, whitespace, and most comments. It replaces literal values with placeholders and transforms multi-row insert statements and IN clauses, to group similar statements with different parameters when measuring how much time is consumed by a particular type of query.

See Also canonical query, query.


The e-mail or other form of communication triggered by an alarm. Notifications are defined using Event Handlers.

See Also alarm.

notification group

A collection of users who should receive a notification when advisor alerts occur. These users might have login credentials for the UI, but this is not a requirement.

See Also alert, Dashboard, notification.



A scripting language typically embedded within web pages.

See Also Connector/PHP.


In the MySQL Enterprise Monitor product, a component that sits between the database and applications that use a particular language-based Connector. It collects query data from both standalone and web-based applications, for MySQL Enterprise Monitor to monitor. For example, there is the MySQL Enterprise Plugin for Connector/Net, and the MySQL Enterprise Plugin for Connector/J. The mechanism for transferring the data, such as whether the data flows through the Aggregator or the Proxy, depends on the particular connector.

See Also Aggregator, Connector, proxy.


An optional subcomponent of the Agent. It can accept queries from user applications, forward them to a MySQL server, and return the query results back to the application. The agent records statistical information about the queries and results. You rearrange the TCP/IP ports so that the application communicates with the proxy instead of the database, either by changing the port where the application communicates with the database, or the port where the database listens.

See Also Agent.



An abbreviation for Query Analyzer used in some keyword names.

See Also Query Analyzer.


In the MySQL Enterprise Monitor context, any SQL statement whose performance might be monitored. Includes not just SQL SELECT queries, but also DML statements such as INSERT, UPDATE, and DELETE, and DDL statements such as CREATE TABLE and TRUNCATE TABLE.

See Also normalized query, slow query log.

Query Analyzer

The MySQL Enterprise Monitor component that tracks data about MySQL queries and summarizes that data using graphs and tables. You interact with it (for example, filtering the displayed queries or selecting a specific time period) using the Query Analyzer tab in the UI.

See Also Dashboard, graph, query, Query Analyzer tab.

Query Analyzer tab

A page within the UI that displays output and controls the options for the Query Analyzer component. See Section 2.6, “The Query Analyzer Tab” for an overview and Chapter 3, Using the Query Analyzer for usage information.

See Also Dashboard, Query Analyzer.



Additional considerations apply when the server you are monitoring is separated from the Service Manager, for example by a wide-area network or by a firewall.

See Also firewall, SSL.


A set of database features that mirrors the same data across a set of servers. Used for reliability in case of server failure, and to speed up queries by dividing the work across servers. Because replication involves so many aspects of reliability and performance, it is an important aspect to monitor and has a dedicated Replication tab in the UI.

See Also Dashboard, Replication tab, topology.

Replication tab

A page within the UI that monitors aspects of replication. See Section 2.7, “The Replication Tab”.

See Also Dashboard, replication.


The database that stores the monitoring data collected by the MySQL Enterprise Monitor product. It can be a separate database instance that is part of the MySQL Enterprise Monitor installation (the bundled MySQL server), or you can use an existing database of your own. The bundled MySQL server is a level of MySQL database that is fully tested with the MySQL Enterprise Monitor product, and can be kept separate from your other databases to avoid any extra load on them. You might use an existing server that has spare capacity, fast storage devices, tuned configuration parameters, a backup system, or other conveniences that can benefit the MySQL Enterprise Monitor data storage as well.

See Also bundled, instance.

ring replication

See circular replication.


A level of access privilege for the UI. One of manager (highest privilege), dba, read-only, or agent (specialized privilege for sending data). Each user account registered with the Dashboard must have one of these roles. Components such as the Agent and the Aggregator use the agent role. To simplify the process of granting credentials for large numbers of users, you can map LDAP roles to these MySQL Enterprise Monitor roles.

See Also Agent, Aggregator, credentials, Dashboard, LDAP.


A test consisting of an expression and one or more threshold values that correspond to different alert levels. When the value of the expression reaches one of the threshold values, an event is generated. Depending on how you configure the rule, the event can result in an alarm, a notification, or both.

See Also advisor, alarm, event, expression, notification, threshold.



Determines how often each advisor is evaluated.

See Also advisor.


A dynamic filter against an asset class.

See Also asset.

Server tree

A section of the UI window that shows individual and groups of MySQL servers. Significant aspects of the Server Tree include the host names of the servers (including the port number if different than the default), and the tooltip information when you hover the mouse pointer over an item in the tree. Selecting one or more items in the tree determines the scope of the information displayed in graphs, Heat Chart, and so on the Monitor tab.

See Also Dashboard, graph, Heat Chart, Monitor tab.

Service Manager

The core MySQL Enterprise Monitor component that receives the monitoring data from the Agent, Aggregator, and Query Analyzer components. It displays this information through the GUI web-interface, and manages all the advisors, rules, and alerts.

See Also advisor, Agent, Aggregator, alert, Dashboard, Query Analyzer, rule.

service request

Generic term for a bug that you have filed or a support request that you have opened, on the My Oracle Support site. Formerly, we referred to these as support issues.

See Also My Oracle Support, support issue.

Settings tab

A page in the UI where you see or change configuration settings for the Service Manager.

See Also Dashboard, Service Manager.


A measure of the seriousness of an alert. Serious alerts trigger alarms.

See Also alarm, alert, rule.


In a replication configuration, a database server that receives updates from a master server. Typically used to service user queries, to minimize the query load on the master. In complex topologies, a server can be both a master and a slave, known as a master/slave.

See Also master, master/slave, replication, topology.

slow query log

A MySQL Server facility for tracking queries that consume considerable time and resources. MySQL Enterprise Monitor provides more information about query performance than the slow query log, and does not currently use the slow query log itself.

See Also query.


The e-mail protocol for sending alerts as e-mail messages. To send alerts this way, you configure e-mail settings similar to those in an e-mail client.

See Also alert.


A protocol for sending event notifications (SNMP traps) to an NMS. The MySQL Enterprise Monitor product can turn notifications for selected rules into SNMP traps. In contrast to typical alerts that are only raised when some issue occurs, SNMP traps are broadcast for all state changes, so that corrective action can be cancelled when an issue is cleared.

See Also alert, NMS, notification.


For MySQL Enterprise Monitor, the default port used for SSL connections is 18443. If you are connecting using SSL, the built-in MySQL Enterprise Monitor certificate is self-signed and may be highlighted as unsafe within the browser on initial connection. To prevent problems accessing the site, add an exception for the certificate to your browser for this server.


The predefined rules and graphs supplied as part of the MySQL Enterprise Monitor product. Contrast with custom.

See Also custom, graph, rule.

support issue

Former term for bugs and service requests. In the My Oracle Support system, now known as a service request, which is the preferred term.

See Also service request.


table scan

See full table scan.


The cutoff value in a rule. When the rule's expression passes this value, an alert is triggered. There can be different threshold values to trigger the different level alerts.

See Also alert, Critical, expression, Informational, rule, Warning.


A component of the Service Manager, the servlet engine that powers the UI.

See Also Apache, Dashboard, Java, Service Manager.


In a replication configuration, the way in which the different master, slave, and dual-purpose master/slave servers are connected. In MySQL Enterprise Monitor, the configurations are classified in the Replication Tab as one of TREE, RING, or MIXED.

See Also master, master/slave, replication, Replication tab, slave.


A data structure often used to represent relationships between MySQL servers. In the UI, servers are displayed in the Server Tree sidebar. In a replication configuration, setting up some machines as dual-purpose master/slave servers produces a nesting relationship that is represented in the Server Tree.

See Also Asset Selector, Dashboard, master/slave, replication, Server tree.



The UI is a web-based interface to the MySQL Enterprise Service Manager. The back end is a Java application powered by the Tomcat server.

See Also Dashboard.


A unique identifier used to distinguish each MySQL instance, host machine, and agent. Because there is so much flexibility in spreading components across multiple systems or running multiple instances and agents on the same system, the combination of these different UUIDs identifies where information came from and the source of any issues. Always generate a new UUID for any one of these components, rather than copying or reusing an existing UUID value.

In MySQL Enterprise Monitor, the UUID for a MySQL server is stored in the table mysql.inventory. When a component such as the Agent or a Connector plugin connects to that MySQL server, the applicable MySQL user must have privileges to read this table.

See Also Agent, instance.



A medium severity level for alarms. Within a rule, you can designate the threshold values that specify for each severity level.

See Also advisor, alarm, alert, Critical, event, Informational, notification, rule, threshold.

What's New tab

A page within the UI that provides updates and news related to MySQL Enterprise Monitor and your My Oracle Support account.

See Also Dashboard, My Oracle Support.