OpenEye: Enterprise-Grade Monitoring at Near-Zero Cost

Complete visibility into your Windows and SQL Server environments

Achieve complete visibility into your Windows and SQL Server environments with a powerful, self-managed, and agentless monitoring solution. OpenEye is a rearchitected, purpose-built performance metrics collector that delivers fast data processing and ingestion without the overhead.

• Effortless Deployment: Get started in minutes with no complex setup or agents to install.
• Real-Time Insights: Gain immediate visibility with live performance dashboards.
• Proactive Monitoring: Identify and address issues before they impact your systems.
• Cost-Effective: Enjoy enterprise-grade capabilities without the enterprise price tag.

What is OpenEye?

OpenEye is a 64-bit, multi-threaded performance data collector for Windows and SQL Server. Using DCOM and command-line operation, it runs on a single central server (Windows Server or Desktop) to gather real-time performance data from hundreds of remote servers. It has no dependencies, making it simple to deploy anywhere.

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Version 2.1 | Windows 64-bit | ZIP Archive| November 2025

Prerequisites

OpenEye uses two open-source applications for data storage and visualization. Both are easy to install and require no specialized knowledge. Download, install, and configure these applications on a network-accessible server before running OpenEye.

1 Install QuestDB

A high-performance time-series database for data ingestion.

Download: https://questdb.com

2 Install Grafana

A leading platform for data visualization and dashboards.

Download: https://grafana.com

3 Install QuestDB Data Source Plug-in

Required for Grafana to connect to QuestDB.

Download: QuestDB Grafana Plug-in

Quick Start Guide

Let's set up monitoring for 25 SQL Servers and their underlying Windows hosts from a central location.

Step One: Configure QuestDB and Grafana

Install QuestDB

Follow the QuestDB installation guide to install it on a server in your network. You can run it as a service or from the command line.

Install Grafana

Similarly, install Grafana on a server in your network, running it as a service or from the command line.

Install the Plug-in

Install the QuestDB data-source plug-in in your Grafana instance.

Add Data Source

In Grafana, create a new data source named qdbopeneye using the QuestDB plug-in. No username or password is required.

Import Dashboard

Import the pre-configured dashboard provided in the OpenEye.zip file into Grafana.

Step Two: Configure and Run OpenEye

Download & Extract

Download the OpenEye.zip file and extract it to a folder, e.g., D:\OpenEye.

Generate Config Files

Run OpenEye.exe twice from the command prompt. This generates the required perf_config.txt and perf_server.txt files.

Configure QuestDB Connection

Open perf_config.txt and update the QuestDB server details:

# QuestDB host name or IP address
QUEST_DB_HOST=localhost
# InfluxDB Line Protocol (ILP/HTTP) port (9000 is the default)
QUEST_DB_PORT=9000

Leave all other parameters unchanged for now.

Add Servers to Monitor

Open perf_server.txt and add your servers using the format described in the next section.

Launch

Start D:\OpenEye\OpenEye.exe.

Important Notes

Permissions: OpenEye uses Integrated Security. The account running it must have WMI read-only permissions on target Windows servers and VIEW SERVER STATE permission on target SQL Servers.

Run as a Service: To run OpenEye as a Windows service, use a tool like NSSM (www.nssm.cc).

Data Ingestion: OpenEye uses the InfluxDB Line Protocol (ILP) over HTTP to write to QuestDB. All tables are created automatically via a schema-on-write mechanism.

Adding or Removing Servers

You can dynamically add or remove servers from monitoring.

1. Edit the perf_server.txt file.
2. To add a server, insert a new line.
3. To remove a server, comment out the line (with a #) or delete it.
4. OpenEye automatically detects these changes. The frequency is controlled by the DURATION_TO_REFRESH_SERVER_MIN parameter (default: 5 minutes).
5. For immediate effect, stop and restart the OpenEye process.

Server Configuration Format

The perf_server.txt file uses the following format:

# Duration | ServerName[,Port] | WIN or SQL
#
# Duration = Collection interval in seconds (0 = use global default)
# ServerName = Windows hostname or IP
# SQLServer[,Port] = SQL Server in format Server\Instance, optional port
# WIN = Collect Windows performance data only
# SQL = Collect both Windows and SQL performance data

Examples

Configuration	Description
5|SRV1967|WIN	Monitor Windows server SRV1967 every 5 seconds.
5|SRV1967|SQL	Monitor SQL Server SRV1967 (default instance) every 5 seconds.
10|SRV1967,2345|SQL	Monitor SQL Server on SRV1967 port 2345 every 10 seconds.
0|SRV1967\SQL2025|SQL	Monitor named instance SQL2025 using the global collection interval.
15|SRV1967\SQL2022|SQL	Monitor named instance SQL2022 every 15 seconds.

Key Configuration Parameters

Parameter	Description
DURATION_TO_REFRESH_SERVER_MIN	How often (in minutes) OpenEye reloads the perf_server.txt file to add new servers or remove commented-out ones.
OPENEYE_RESET_INTERVAL_MIN & OPENEYE_RESET_AT	Controls how often OpenEye performs a full reset. OPENEYE_RESET_INTERVAL_MIN=720 (12 hours) OPENEYE_RESET_AT=12:01AM (Resets daily at 12:01 AM). If blank, the interval parameter is used. During a reset, OpenEye restarts all monitoring threads, re-reading all configuration files.

External TSQL and WQL Queries

OpenEye allows you to extend its functionality by using your own custom queries, and can even replace its built-in data collection.

Configuration (perf_config.txt)

# Enable/Disable built-in collectors
USE_BUILTIN_WMI_COLLECTOR=YES
USE_BUILTIN_SQL_COLLECTOR=YES
# Enable external custom queries
USE_EXTERNAL_WMI_QUERY=YES
USE_EXTERNAL_SQL_QUERY=YES

Query File Format

1. Place WQL queries in the \wqlqueries folder and TSQL queries in the \sqlqueries folder.
2. WQL File Name Format: wql_[CustomName]-[Duration].txt
3. TSQL File Name Format: sql_[CustomName]-[Duration].txt
   • The prefix (wql_/sql_) is mandatory.
   • [CustomName] defines the resulting table name in QuestDB.
   • [Duration] is the execution interval in seconds. If omitted, the global default is used.

Sample Queries (included in the package)

WQL Queries

• wql_transactions-15.txt → Creates table wql_transactions, runs every 15 seconds.
• wql_volume-10.txt → Creates table wql_volume, runs every 10 seconds.

TSQL Queries

• sql_host_memory-30.txt → Creates table sql_host_memory, runs every 30 seconds.
• sql_single_useplan-60.txt → Creates table sql_single_useplan, runs every 60 seconds.
• sql_waittype-15.txt → Creates table sql_waittype, runs every 15 seconds.

Note: For SQL Server-related WMI classes, use the placeholder [WQLSQLName] in your query. OpenEye will automatically substitute the correct WMI class name based on the server and instance defined in perf_server.txt.

Monitoring Hundreds of Servers

Scaling OpenEye for Large Environments

While OpenEye can collect performance metrics from hundreds of servers without restrictions, each OpenEye process is optimized to monitor 32-48 remote servers due to its DCOM and RPC-based architecture. For optimal performance, we recommend limiting each instance to a maximum of 48 servers.

To monitor 200 servers from a central location:

1. Divide your 200 servers into 5 groups of 40 servers each
2. Create a main directory: D:\OpenEye
3. Create 5 sub-folders: D:\OpenEye\sub-01, D:\OpenEye\sub-02, etc.
4. Copy the perf_config.txt file into each sub-folder
5. Create individual perf_server.txt files in each sub-folder with the corresponding server groups
6. Copy the \wqlqueries and \sqlqueries folders along with OpenEye.exe to each sub-folder
7. Use NSSM to create a unique Windows service for each sub-folder instance
8. Optionally, use OPENEYE_SERVICE_NAME='Service Name' in your config to identify each service, or leave blank to use the sub-folder name

Sample OpenEye Management panel

Note: This distributed approach ensures optimal performance and resource utilization when monitoring large server environments.