Server Monitoring: Agent-based vs. Agentless

A comparison of Site24x7's agent-based monitoring and agentless monitoring approaches.

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Is it better to install an agent on every server to monitor its performance, or should you go for an agentless monitoring approach? Agentless versus agent-based monitoring—therein lies the dilemma. To help you decide the best method to handle your infrastructure problems, we've listed the metrics you receive with the agent-based and agentless monitoring approaches. With this information, you can select the best approach to fit your environment. But before going over the specifications, let's first look at when you should select agent-based server monitoring and when to go for agentless server monitoring.

When to use agent-based monitoring

When to use agentless monitoring

If you do not want any third-party programs installed on your servers, it is advisable to go for an agentless approach. Additionally, an agentless server also allows for you to monitor any OS flavor, as well as custom servers that don't allow for the installation of server agents. If any of these limitations are relevant to your network environment, then using an agentless monitor is the way to go.

Agent-based vs. Agentless monitoring

Attribute Site24x7 Agent-based Monitoring Site24x7 Agentless Monitoring
Methodology Install Site24x7's server monitoring agent on every server. Install Site24x7's On-Premise Poller on the server's network.
How it works The agent collects data by executing commands and scripts directly in each server's operating system. The On-Premise Poller connects to servers and collects data using SNMP or WMI.
Note: Every server must enable SNMP or WMI protocol to communicate with the On-Premise Poller.
Installation methods 1. Install a Site24x7 server agent individually on every server.
2. Bulk installation methods for Windows and Linux are available.
Install the On-Premise Poller on your server network and add an individual server IP address/hostname or by specifying the IP range.
Connectivity to the internet Access to the internet is not mandatory for all servers. Agents in the intranet servers can send the data to Site24x7 through a proxy server connected to the internet. Outbound access to the internet for the On-Premise Poller is sufficient to collect server metrics.
Data transfer to Site24x7 A one-way HTTPS connection that sends data to Site24x7 using the secure SSL protocol. The On-Premise Poller uses an HTTPS connection to send data to Site24x7.
Credentials Does not require credentials. Requires SNMP or WMI credentials.
Supported versions: SNMPv1/v2 and SNMP v3.
Dedicated server Does not require a dedicated server for Site24x7. Requires one dedicated server machine for running the On-Premise Poller. We support a maximum of 500 servers per Poller.
Log management For log management, use the AppLogs agent to access the logs in the local server. Cannot access the application logs without an agent.
Status checks and real-time alerting Performs one-minute status checks to provide near real-time notifications. Performs one-minute status checks and has a poll frequency of five minutes to collect the performance metrics.
Supported OS types Windows, Linux, macOS, and FreeBSD. Any server that supports SNMP or WMI protocol can add the agentless server.
CPU metrics
CPU utilization
CPU utilization by core
Idle time, wait time, hardware, and software interrupts time
Memory metrics
Memory utilization
Swap memory utilization
Memory pages (in/out/faults)
Disk metrics
Disk utilization
Individual disk utilization
Disk I/O speed
Disk idle and busy percentage
Process monitoring
Process CPU usage
Process memory usage (percentage)
Process memory usage (bytes)
Process instance count
Process thread and handle count
Services monitoring
CPU usage (percentage)
Memory usage (percentage)
Instance count
Thread count and handle count
Response time
Performance counters
Custom performance metrics Yes. Through custom plugins that collect data through Shell scripts. Yes. Supports custom SNMP counters (tabular and scalar).
I/O traffic
Packets received and transmitted
Errors count
Errors percentage
Discard count
Discard percentage
Admin/Operational state 
Integrates with plugins
Resource checks
File, directory, syslog, and event log checks
Microsoft Applications
IIS, SQL, Exchange, BizTalk, SharePoint, Office 365, Active Directory, Failover Cluster, Hyper-V, and Windows Backup
IT automation
Incident remediation through the configuration of scripts that get executed automatically on downtime.
Alerting and reporting
SMS, email and voice call
Performance reports
Licensing model Each server monitoring agent is considered as two basic monitors. Each server monitor is considered two basic monitors.

This Comparison was updated on 09 August, 2022. All trademarks and registered trademarks are the property of their respective owners.

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