Multiple Instance Monitoring

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While you can monitor only one instance in Monitoring a Database Instance, Monitoring Multiple Instances allows you to see and compare the metrics for multiple instances on a screen. You can quickly see the status of instances through grouped values of instance metrics such as running agent count, total number of active sessions, and transaction information. Graph charts make it easy to see how instances' metric values are trending and which instances have higher metric values. It provides information of the longest lasting active session.

Multi-instance Monitoring

Tip

If you select an agent to compare in Dashboard > Instance List, and then select Multi view, the Monitoring Multiple Instances menu appears.

Viewing the past data

The dashboard basically provides real-time monitoring features in which you can view the past data.

Real-time mode	Non-real-time mode

Select in the time selector at the upper left of the screen.
Click the date and time to set the desired time zone.
Select Apply.

It updates the data in widgets placed on the dashboard based on the set time. To switch to the Realtime mode, select .

Checking the agent

Checking the agent connection status

On the upper left of the screen, the right area of the time selector provides information that allows you to check the status of agents connected to the project. This allows you to immediately check whether the target application server is running.

Total: Number of all agents connected to the project
Active: Number of active agents
Inactive: Number of inactive agents
: Can display or hide inactive agents.

Agent-based monitoring

Selecting the agent

By default, the dashboard displays the metrics collected from all agents in charts and you can also view the data by agent. Select one or more agents under the time selector. The data of the widgets on the dashboard is updated with the metrics of the selected agent(s).

Tip

To select all agents again while one or more agents is selected, deselect them or select Total.

Note

If there are numerous agents connected to the project, it is efficient to set the agent names to be short. For more information about the agent name setting, see the following.

Monitoring each classified agents

Select agent by category

You can select and monitor agents by each group classified through agent settings.

Agent: You can select an individual agent or all agents.
Agent by cluster: In case of the database that consists of multiple clusters, agents can be monitored by cluster.

The widgets on the dashboard can be adjusted to the desired size and placed in the desired positions. You can also delete unnecessary widgets or add them again.

Click and hold the mouse on the Resize icon element at the lower right of the widget, and then drag it to the desired size. Grids with a uniform horizontal-to-vertical ratio appear and the size of the widget can be adjusted in each grid.

When you move the mouse cursor to the top of the widget, the cursor shape changes to Move icon . At this time, you can move the widget by dragging with your left mouse button and move to the desired position.

Right-click on a widget to delete. If you select Delete, the widget is deleted from the dashboard.

Move the mouse cursor to an empty space on the dashboard and then right-click on it. Select a widget to add from the pop-up menu. Place the widget to the desired position and then resize it.

Note

For more information about the widgets that can be placed on the dashboard, see the following.
The widgets that can be added are fixed, but we plan to increase supports through future updates.

The icons displayed on the widget function as follows:

: You can see the features and information for major widgets. (multilingual support planned)
or : You can enlarge or reduce the range of the vertical axis.
: You can view the widget's data on a wider screen.
: A detail window appears where you can search the data of the widgets separately by agent.

Note

The provided options may differ depending on the widget.

Preset

You can save and load the settings and layouts for widgets on the dashboard. The default preset (Default) cannot be changed, but you can create a new preset by resizing and placing widgets in the desired format.

Creating a new preset

Place the widgets in the desired format on the dashboard. You can also resize and place only the widgets to be frequently checked.
On the upper right of the screen, select .
Enter a new preset name.

To save the selected agent data, select Include agent selection history.
Select Save.

You can see the newly saved preset from the preset list.

Note

If any changes are made to the newly created preset, save the preset again. Select and then save the preset with the same name. Any changes are overwritten in the existing preset.
If you go to another menu without saving changes on the dashboard, the changes are not saved.
Presets are saved in your user account and cannot be shared with other users. We plan to update it for better features.

Deleting presets

If you have unused presets, you can delete them from the preset list. Select on the right of the item to delete from the preset list.

The types of widgets that can be placed on the dashboard are as follows.

DB Status

You can see the status of agents (instances) in the project. Individual agents are displayed in a hexagon. If you hover your mouse over it, the current status and IP address appear.

The status of the agent can be classified as follows:
- Normal: Number of normal agents.
- Inactive Agents: Number of disconnected agents.
Clusters

You can see the status of Master and Slave instances.
Instantaneous Ops Per Sec

It displays the number of commands per second (instantaneous_ops_per_sec) processed by the server using a pie chart. It can be used as a metric to compare and monitor the performance between multiple instances.

Tip
The instantaneous_ops_per_sec metric indicates the number of commands per second that the server processes. This is useful for tracing and monitoring the workload that your instances are currently handling. The number of commands per second indicates the amount of commands the server receives and processes. It helps you check the server's workload and identify performance issues.
Key Status

It monitors the server's key status. It is necessary to understand the database running status and optimize its performance.
- Evicted Keys: Displays the number of cached or stored keys that have expired or deleted according to the memory policy. If the Evicted Keys metric increases, there may be an issue of insufficient memory or a cache policy issue.
- Expired Keys: Displays the number of expired keys. In Redis, you can set the expiration time for keys, and the expired keys are deleted automatically. If the Expired Keys metric increases, you may need to review the expiration policy in the database or check user behaviors.
- Keyspace Hits: Displays the number of successful requests to find in cache or memory while retrieving and loading keys from the database. The metric helps you evaluate the cache efficiency and understand the access patterns to keys.
- Keyspace Misses: Displays the number of unsuccessful requests to find in cache or memory while retrieving and loading keys from the database. The metric helps you evaluate the cache efficiency and take measures for performance improvement.
Note
In the Redis database, the keys include various data types such as strings, hashes, lists, sets, and ordered sets.
Connected Clients (connected_clients)

Number of the connected clients. You can see the number of concurrent connections to the server. A rapid increase in the number of client connections to the server can indicate an unexpected increase in traffic or other issues. Accordingly, you need to recognize and respond quickly to the issues.
Used Memory (used_memory)

Amount of memory (bytes) requested for data saving. There may be a difference from the amount of memory allocated by the OS. If the used_memory metric is too high, it may be required to review the memory management policy and optimize the dataset to reduce the memory usage.
Total Commands (total_commands_processed)

A widget that displays the total number of commands processed after the server startup. It represents the cumulative number of all commands performed by the server and includes the number of requests from all clients processed while providing services. The total_commands_processed metric is useful for finding the level of server activities and evaluating the performance. This metric increases over time and you need to continuously monitor the activity level of the server by tracing value changes.
Used CPU (used_cpu)

Redis uses a single CPU per instance and displays the allocated CPU usage. The used_cpu metric can help you understand how the server uses CPU resources. If this metric increases to an unexpected level, it is required to recognize any performance issue and optimize the performance.
Commands(/S) (instantaneous_ops_per_sec)

It displays the number of commands per second (instantaneous_ops_per_sec) processed by the server for each instance over time through the time series chart. This widget is useful for monitoring trends over time and identifying performance trends and issues.

Tip
The instantaneous_ops_per_sec metric indicates the number of commands per second that the server processes. This is useful for tracing and monitoring the workload that your instances are currently handling. The number of commands per second indicates the amount of commands the server receives and processes. It helps you check the server's workload and identify performance issues.
Total Net Input Bytes

Widget that displays the total amount of network input (bytes) received by the server. It measures the total amount of all network traffic received from clients. This widget helps you see how much network bandwidth the clients have consumed while communicating with the server. It may be useful for tracing the client activity levels and managing the network load.
Blocked Clients (blocked_clients)

It displays the number of clients in a blocked state on the server. A blocked client is waiting for specific tasks on the server and the client is blocked until the pending task is completed. You can monitor how many clients are in a blocked state. This metric allows you to easily see the current load status of the server.
Keys Total (keys_total)

Total number of keys saved in the Redis database. The keys include various data types such as strings, hashes, lists, sets, and ordered sets. By tracing the overall amount of data saved in the database, you can see the database size and trace the data growth trend. If this metric rapidly increases, you may need to allocate additional memory or review the data cleaning policy.
Evicted Keys (evicted_keys)

Number of keys removed due to the database's maxmemory limit. The removal policy is based on the maxmemory-policy setting in the configuration file. In general, the evicted_keys metric increases when the validity period of the key data expires or the key is deleted due to insufficient memory. By monitoring the evicted_keys metric, you can trace how often keys are deleted and identify the memory usage and performance.
Keyspace Hits (keyspace_hits)

Number of successful key inquiry requests. If the value get key exists, it is incremented by 1. Hit Rate can be calculated as (keyspace_hits / (keyspace_hits + keyspace_misses) * 100 ). The keyspace_hits metric is one of the important metrics for evaluating the cache efficiency and performance of the database server.
Rdb Changes Since Last Save

A widget that represents the amount of data changed after the last SAVE command. By tracing the amount of changed data, you can see the changed amount of data. If you have a large amount of changes, adjust the backup cycle or review the data backup policy to reduce the possibility of data loss.
Total Net Output Bytes

A widget that displays the amount of all network traffic sent by the database server to its clients. You can trace the activities of the server sending data to clients. This allows you to evaluate the server's response speed and the performance to handle client requests.

You can view real-time active sessions in the Session Table widget at the bottom of the screen.

Note

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

Filtering the table data

Filter

Select on the upper right of the table.
Select a column header and a condition in the table.
Enter a desired value in the Enter conditions field.
Select Save.

Configuring the table columns

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

Column Settings

Note

After configuration, select OK 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.

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 Reset.

Column information guide

Active session
Process information

It is the description of column items in the Active sessions table. For more information, see the following link.

Item	Description
id	Unique 64-bit client ID
addr	Client IP address and port number
age	Total connection time
cmd	Last executed command
db	Current database ID
events	`r`: Can read the client socket (event loop) `w`: Can write the client socket (event loop)
fd	Client socket file's descriptor (file descriptor) number
flags	The client type, N indicates normal client. (normal/master/replica/pubsub)
idle	Time (seconds) whose connection status is idle.
multi	Number of commands in the MULTI/EXEC context
obl	Output buffer length
oll	Output list length (response is queued to this list if the buffer is full)
omem	Amount of memory the client uses for output buffers
psub	Number of matched subscription patterns
qbuf	Query buffer size (0 is not query dependent)
qbuf-free	Query buffer free space (0 indicates the buffer is full, no free space)
sub	Number of subscription channels
user	Client's authenticated username

Note

WhaTap basically stores the client-related 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

Downloading the view list

You can download the current Session Table list in CSV format. Select on the upper right of the Session Table section.

The naming format of the downloaded file is as follows:

Active sessions: activeSession_HH_MM_SS.csv

Viewing in a new window

You can see the Session Table list on a new wider screen. Select on the upper right of the Session Table section.

This widget provides the Redis cluster status and configuration data in a table format. You can see the overall health of the cluster of multiple instances at a glance.

The data for each column in the table is as follows:

instance: Name or identifier of each instance in the cluster.
cluster name: Name of the cluster to identify a cluster.
flags: Flag indicating the status or characteristics of each instance.
ip: IP address of each instance.
link status: Connection status of each instance.
slots: Slots used in the cluster. Each slot is a part of data in the cluster. This information helps you find the data distribution and load balancing status in the cluster.

Multiple Instance Monitoring

Viewing the past data