Monitoring a Database Instance

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In Monitoring a Database Instance, you can monitor the key metrics of the database server, information details on active sessions, lock tree, PQ tree, and process information in real time. You can also see the alerts that could be problematic warnings. By default, the collected data for the last 10 minutes is retrieved in real time. Collected data is updated every 5 seconds.

Basic screen guide

Selecting the lookup time and target

By default, the collected data for the last 10 minutes is retrieved in real time. If you select values in Time and Instance, the collected data is automatically applied to the graph chart and Active sessions table.

• To view the past data, click the green button in Time and then select the desired lookup time. You can search data up to the last 3 weeks.

• To query a random date and time, select the button in Time. If you click the text range for date and time, the option appears to select the date and time. To search data in real time again, select .

• To search data from other agents, click Instance and then select a desired agent name.

Graph chart section

Default displays 16 metrics saved as presets as a graph chart widget. The horizontal axis of each widget is time, and the vertical axis is the metric number. To know the meaning of each metric, select next to the name or see the following.

• To change the position with another widget, select and drag the upper part of the widget. However, the size of the widget cannot be changed.

  

• When a specific time is selected in the widget, the real-time inquiry mode is stopped and the active sessions performed at the selected time zone appear in the Active sessions table. After that, a button that allows you to view the data every 5 seconds appears on the Active sessions table.

  

  Note

  • The selected time can be seen on the upper right of the Active sessions table.

  • In the Active sessions table list, the text colors are changed black → orange → Red, which means that the performance of the session is getting slower.

Active Sessions / Lock Tree / Process Info

You can search active sessions, lock trees, and processes information in real time. If you select a specific time of the chart in the widget, the real-time inquiry mode is stopped and the session performed at the selected time appears in the table. A time selection button appears above the table to search data in 5-second increments.

• Active sessions: You can view active sessions and queries.

  • If you select a session running, the Session detail window appears. You can see the details for the selected session. For more information, see the following.

  • If you select an item in the rightmost query column in the table, the SQL details window appears. You can see the full text and plan information for the selected query. For more information, see the following.

• Lock tree

  You can see the lock session information, and holder and waiter information in real time. For more information about the table columns, see the following.

• Process Info

  You can query the resource usage of the database server in real time.

Tip

By adding a linked project, you can view information details about active transactions associated with active sessions in the Active sessions table in real-time. For more detailed information about adding and using a linked project, see [the following] (linked-projects).

Note

• In the table list, the text colors are changed black → orange → Red, which means that the performance of the session is getting slower.

• The Process Info can be checked only when the XOS agent has been installed. For more information, see the following.

Selecting metrics

To add or replace the metric graph to the widget, select on the upper right of the widget. The Metric Select window appears. After completing the desired settings, select Save.

• Preview: You can preview the graph for the selected metric.

• Title: Enter the widget name.

• Recommendation Metrics / All Metrics: If you select Recommendation Metrics, the list of frequently viewed metrics in Database Monitoring appears. The metrics displayed in the list can be changed or added in the widget.

• In the area, you can see the trend of metrics in a graph and add or change any widget. By selecting a desired tab, you can narrow down the list of metrics according to the category.

Adding metrics

Multiple metrics can be added in a widget. You can add up to four metrics.

1. Select on the upper right of the widget to add the metrics in.

2. If the Metric Select window appears, in the metrics list or graph list, select on the right of the metric to add.

3. To add more metrics, repeat the step 2.

4. To easily identify the widget, change the Title.

5. Select Save on the lower right of the screen.

Charts are generated as many times added to the widget to which metrics are added. If you select next to the widget name, you can see the name and description of the added metric. You can also check the figure through a tooltip by hovering your mouse over the chart.

Note

The tooltip of the button is not supported in multiple languages.

Changing a metric

You can change a metric in the widget to another.

1. Select on the upper right of the widget to change the metrics.

2. If the Metric Select window appears, select a metric to change in the area.

3. In the metrics list or graph list, select a desired metric.

4. In the area, check that the name of the selected metric has been changed.

5. Select Save on the lower right of the screen.

Deleting a metric

You can delete unnecessary metrics while multiple metrics have been set in the widget.

1. On the upper right of the widget to delete metrics from, select .

2. If the Metric Select window appears, select on the right of the metric to delete from the area.

3. Select Save on the lower right of the screen.

Note

At least one metric must be selected for a widget. You cannot delete all metrics in a widget.

Preset

You can save and recall user-defined widget settings and active session table arrangements as presets. The following presets are provided by default, and the Default presets cannot be changed.

• Default: It consists of major DB metrics.

• Default(xos): It consists of key DB metrics and XOS metrics (CPU and memory utilization, memory SWAP usage, disk I/O, etc.).

• Default(rds): It consists of key DB metrics and RDS CloudWatch metrics (CPU utilization, free memory space, free storage space, network, etc.).

Save Preset

1. Add or modify the widget metrics.

2. On the upper right of the screen, select .

3. In Save preset, change the name and then select Save.

In the Preset list, select a saved item to fetch the settings.

Note

• The Default preset cannot be modified.

• You can create custom presets up to 5. Including the modified metric graph, the column order, column width, and filter application content of the active sessions are also applied.

Deleting presets

If you select Preset on the upper right of the screen, the preset list appears. Select on the right of the preset to delete.

Using the active session section

Through Active sessions at the bottom of the screen, you can see the real-time active sessions. The following provides the guide for the button on the upper right of the table.

• : Using the column header entries in the table, the list can be filtered.

• : The list of tables is refreshed.

• : The column header entries in the table can be displayed or hidden.

• : The active session can be stopped.

  Note

  This feature is only available to the members with Edit role. For more information about member roles, see the following.

• : You can download the content of the table as a CSV file.

• : A new window appears to see the list on a wider screen.

Checking the SQL statistics

You can see the list of top SQLs for the time period along with the trend of key performance metrics that occurred during the specific time in the past.

1. In Time, select to switch from real-time mode to non-real-time mode.

2. In Time, set the time zone to view.

3. On the upper right of the Active sessions area, select SQL statistics.

SQL statistics appears in a new window. In Instance monitoring, you can see the top SQL list executed for the set time. For more information about SQL statistics, see the following.

Checking the session information details

If you select a session in the Active sessions tab, the Session detail window appears. You can see the information details about the selected session.

• The session information is viewed in real time by default. If you select in the time selector, you can stop a real-time view and see the data based on the paused time. To refresh data while pausing a real-time view, select .

• Kill Session: You can stop the selected session. If the Session kill window appears, enter the password (Parameter Key) and then select Apply.

  Note

  This feature is only available in real-time viewing mode.

• Session history: You can go to the Session History menu to see the records of the selected session.

  Note

  For more information about Session History, see the following.

• Session Info: You can see the basic information of the selected session and the information details including the status.

• Wait Info: The waiting event and waiting time of the selected session are provided. You can also see information about the waiting events that occur when the database system is waiting to execute a specific task.

• SQL Text / Plan: You can see the SQL query statements and plans of the selected session. For more information, see the following.

• Process Info: You can see the process information details of the selected session.

See query details

To check the SQL query information of the executing session, select the query (or sql_text) column in the Active sessions section. The SQL details window appears. You can check the SQL query statements and plan information.

• View SQL Statistics: You can go to the SQL statistics menu where you can check statistical information related to the SQL query statement.

• Default Bind: You can bind the part set as a variable in the query sentence to the default value.

• Reset Bind: You can release the bound default value and check the variable.

• Formatting: You can improve readability by applying indentation and formatting to a SQL query statement.

• Plan: To check plan information, enter DB Name, User Name, and Password, and then select .

  • Text: You can check plan information in text format.

  • JSON: By viewing the plan information in Json format, you can quickly find the points where bottlenecks occur.

  Note

  The function to view plan information in JSON format is supported only in DBX agent 1.6.12 or later.

Tip

If you select a table or index while viewing the plan information in JSON format, the Object detail window appears where you can see the configurations for columns and index items in the table.

This function is supported in DBX agent 1.6.15 or later. For more information about the database roles and related settings, see the following.

Checking the linked projects

In Correlated Project Management, when another application project is added, the button is added to the active session entry.

Through the Correlation analysis window that appears when the button is selected, you can check active transactions of the applications linked to active sessions. You can check specific metrics such as transaction ID, thread ID, client IP, and CPU usage time, along with basic information such as transaction URL and database connection information, DB type, HTTP method, and execution time. Additionally, you can monitor the SQL query execution time, number of SQL calls, DB connection time, and such, which allows you to comprehensively analyze the system performance.

In particular, it provides the call stack information and SQL queries through stack traces, helping you trace and resolve detailed causes when problems occur. This allows you to perform in-depth analysis of interactions between applications and databases, and to quickly diagnose performance bottlenecks.

Note

For more detailed information about adding and using a linked project, see [the following] (linked-projects).

Stopping an active session

1. Select on the upper right of the table.

2. Select the session to stop from the table list. You can select multiple items.

3. Select Stop.

4. If the Session kill window appears, enter the password (Parameter Key).

   

5. Select Apply.

The selected session is stopped.

Note

• Through the paramkey.txt file in the DBX agent installation path, you can find the password.

• This function can be used by only the members with the Edit role. For more information about the member roles, see the following.

Zooming in the graph chart section

If the current screen is small and difficult to check the widgets, you can see the graph chart widget on a wider screen. Select at the bottom of the Active sessions section. The Active sessions section is collapsed and the graph chart widget section is expanded.

To zoom out the graph chart widget, select at the bottom of the Active sessions section.

Setting the table columns

You can hide the table header columns or add any of them. You can also change the column order. Select .

Note

• After configuration, select Confirm to apply the settings in the table.

• In the search bar, enter text to search the desired columns. Only the columns that meet the entered text are displayed.

• Images may differ depending on the product, project, or menu.

Adding columns

From the list, select the items to add as table header columns. To select all items, select Select All.

Deleting columns

From the list, unselect the columns to delete. Alternatively, select on the right of the item to delete from the list.

Changing the column order

Drag an item to reposition from the list, and then move it to the desired position.

Initializing the configuration

To cancel all changes and reset them, select Initialized.

Filtering the table data

1. Select on the upper right of the table.

2. Select a column header and a condition in the table.

3. Enter a desired value in the Enter conditions field.

4. Select Save.

Column information guide

Active session

Item	Description
pid	Process ID
db	Database name
user	SQL execution account
application	Client application name
client_host	Host name of the connected client (reported by reverse DNS lookup of client_addr)
client_addr	Client IP address
client_port	Client port number (in case of using the UNIX socket -1)
query_hash	Hash value of query (internal WhaTap control value)
query_start	Time when the active query started (if the state is not active, it is the last query started time)
state	Current status of the backend process (active, idle, etc.)
state_change	Last time when the state was changed
xact_start	Time when the current transaction for the process started (null if no transaction is active)
backend_start	Time when the backend process started
backend_xmin	Minimum value of xid whose backend process is being processed
backend_type	Type of the backend process (e.g. autovacuum worker, logical replication launcher, client backend, checkpointer)
backend_xid	xid whose backend is being processed
wait_event_type	Type of the event whose backend process is in standby
wait_event	Waiting event name where the backend process is in standby

Note

WhaTap basically stores the client-related information.

Lock tree

Item	Description
holder type	Type of the holder session (transaction ID, tuple, etc.)
lock mode	holder_mode (exclusive lock, shared lock, etc.)
waiter type	Type of the waiter session (transaction ID, tuple, etc.)
lock request	waiter_mode (exclusive lock, shared lock, etc.)

Process information

The following items are the metrics collected if the XOS agent has been installed.

Item	Description
cputime	CPU usage time
cpuusage	CPU Utilization
elapse	Elapsed time of CPU usage
vsize	Virtual memory size (Kb)
rss	Resident Set Size (RSS) that is the number of physical pages associated with the process.
state	Process status
ioread	Actual time spent reading the block (milliseconds)
iowrite	Actual time spent writing the block (milliseconds)
pss	Process specific memory usage + Percentage of shared memory occupied by one process
uid	user id
cmd	Executing command
longcmd	Full path of cmd