Part 5: Searching and Analyzing Logs in Graylog

Learn how to search and analyze logs in Graylog, a powerful open source log management platform. Find out how to create dashboards, widgets, alerts, and more.

Table of Contents

1. Introduction

In this tutorial, you will learn how to use Graylog’s powerful search and analysis features to find and visualize the information you need from your logs. Graylog is an open source log management platform that allows you to collect, store, and analyze logs from various sources. You can use Graylog to monitor the performance and health of your systems, troubleshoot issues, and gain insights into your data.

Searching and analyzing logs in Graylog involves three main steps:

Using the search bar to enter a query and filter the results by time range, streams, and fields.
Creating dashboards to display the results of your queries in various widgets and visualizations.
Configuring alerts and notifications to get notified when certain conditions are met or thresholds are exceeded.

By the end of this tutorial, you will be able to:

Search logs in Graylog using the search bar, filters, and operators.
Save and share your searches with other users.
Create dashboards to visualize your log data in different ways.
Add widgets and visualizations to your dashboards, such as charts, graphs, tables, maps, and more.
Configure alerts and notifications to monitor your log data and get notified of important events.

To follow this tutorial, you will need:

A Graylog server up and running. You can follow the official installation guide to set up your own Graylog server, or use a Graylog Cloud account.
Some log data ingested into Graylog. You can use the official documentation to learn how to send data from various sources to Graylog, or use the Graylog Marketplace to find ready-made integrations and plugins.
A basic understanding of how Graylog works and how to use its web interface. You can refer to the Getting Started section of the official documentation for an overview of Graylog’s features and functionality.

Ready to start searching and analyzing your logs in Graylog? Let’s begin!

2. Searching Logs in Graylog

The first step to searching and analyzing your logs in Graylog is to use the search bar. The search bar allows you to enter a query and filter the results by time range, streams, and fields. You can use the search bar to quickly find the logs that match your criteria and explore the data in more detail.

To use the search bar, follow these steps:

Go to the Search page in the Graylog web interface.
Enter your query in the search bar. You can use keywords, phrases, or operators to specify your search criteria. For example, you can use error to find all the logs that contain the word error, or source:webserver to find all the logs that come from the webserver source. You can also use boolean operators such as AND, OR, and NOT to combine multiple criteria. For example, you can use error AND source:webserver to find all the logs that contain the word error and come from the webserver source.
Select the time range for your search. You can use the drop-down menu to choose a predefined time range, such as Last 5 minutes, Last hour, or All messages. You can also use the calendar icon to select a custom time range, or the clock icon to enter a relative time range, such as last 30 minutes or from 10 minutes ago to now.
Select the streams for your search. Streams are a way to group and filter logs based on certain criteria, such as source, message, or field. You can use streams to organize your logs into different categories and focus on the ones that are relevant to your search. You can select one or more streams from the drop-down menu, or use the All messages option to search across all streams.
Select the fields for your search. Fields are the attributes of each log message, such as timestamp, source, message, level, or any custom field that you have defined. You can use fields to display and sort the information that you want to see in your search results. You can select one or more fields from the drop-down menu, or use the All fields option to display all fields.
Click the Search button or press Enter to execute your search.

You will see the search results in the main area of the page, showing the log messages that match your query and the fields that you have selected. You can use the pagination buttons to navigate through the results, or the sorting options to order the results by relevance or timestamp. You can also use the histogram chart to see the distribution of the results over time, and the field statistics table to see the summary of the values for each field.

Using the search bar, you can quickly and easily find the logs that you are looking for and get an overview of the data. But what if you want to dig deeper and perform more advanced analysis? That’s where the next step comes in: applying filters and operators.

2.1. Using the Search Bar

Using the search bar, you can quickly and easily find the logs that match your criteria and explore the data in more detail. But sometimes, you may want to refine your search results and perform more advanced analysis. That’s where the next step comes in: applying filters and operators.

Filters and operators are additional tools that you can use to modify your query and narrow down your search results. You can use filters and operators to specify the exact conditions that you want your logs to meet, such as the values of certain fields, the ranges of numerical or date values, the presence or absence of keywords, and more.

To apply filters and operators, follow these steps:

Click on the Filter button next to the search bar. You will see a drop-down menu with various options to filter your results by field, value, or operator.
Select the field that you want to filter by. You can choose from the fields that you have selected in the previous step, or use the All fields option to filter by any field.
Select the value that you want to filter by. You can enter a specific value, such as error or webserver, or use a wildcard character, such as * or ?, to match any value or any single character. You can also use the Quick values option to see the most common values for the selected field and choose one of them.
Select the operator that you want to apply. You can use the following operators to compare the values of the selected field:

= (equal to)
!= (not equal to)
< (less than)
<= (less than or equal to)
> (greater than)
>= (greater than or equal to)
EXISTS (exists)
NOT EXISTS (not exists)

Click on the Add filter button to apply the filter to your query. You will see the filter added to the search bar and the results updated accordingly.
Repeat the steps above to add more filters to your query. You can use the AND or OR buttons to combine multiple filters with logical operators.
Click on the Search button or press Enter to execute your query with the filters applied.

You will see the search results filtered by the conditions that you have specified. You can use the Remove button to remove any filter from your query, or the Clear button to remove all filters and start over.

Applying filters and operators, you can fine-tune your search results and get more precise and relevant information from your logs. But what if you want to save your query and share it with others? That’s where the next step comes in: saving and sharing searches.

2.2. Applying Filters and Operators

To apply filters and operators, follow these steps:

Click on the Filter button next to the search bar. You will see a drop-down menu with various options to filter your results by field, value, or operator.
Select the field that you want to filter by. You can choose from the fields that you have selected in the previous step, or use the All fields option to filter by any field.
Select the value that you want to filter by. You can enter a specific value, such as error or webserver, or use a wildcard character, such as * or ?, to match any value or any single character. You can also use the Quick values option to see the most common values for the selected field and choose one of them.
Select the operator that you want to apply. You can use the following operators to compare the values of the selected field:

= (equal to)
!= (not equal to)
< (less than)
<= (less than or equal to)
> (greater than)
>= (greater than or equal to)
EXISTS (exists)
NOT EXISTS (not exists)

Click on the Add filter button to apply the filter to your query. You will see the filter added to the search bar and the results updated accordingly.
Repeat the steps above to add more filters to your query. You can use the AND or OR buttons to combine multiple filters with logical operators.
Click on the Search button or press Enter to execute your query with the filters applied.

2.3. Saving and Sharing Searches

Using the search bar, you can quickly and easily find the logs that match your criteria and explore the data in more detail. But sometimes, you may want to save your query and share it with others. That’s where the next step comes in: saving and sharing searches.

Saving and sharing searches allows you to store your query and its parameters for future use, and to share it with other users or external applications. You can use this feature to create reusable searches, collaborate with your team, and integrate Graylog with other tools.

To save and share your search, follow these steps:

Click on the Save button next to the search bar. You will see a pop-up window where you can enter a name and a description for your search.
Enter a name and a description for your search. The name should be descriptive and unique, and the description should provide some context and information about the purpose and scope of your search.
Click on the Save button to save your search. You will see a confirmation message and a link to your saved search.
Click on the link to go to your saved search. You will see the same query and results that you had before, but with a different URL and a Saved searches menu on the top right corner.
Use the Saved searches menu to manage your saved search. You can do the following actions:

Load: Load a different saved search from the list of available ones.
Update: Update your current saved search with any changes that you have made to the query or the parameters.
Delete: Delete your current saved search from the list of available ones.
Share: Share your current saved search with other users or external applications. You can choose from the following options:

Share with users: Share your saved search with other users who have access to Graylog. You can select the users or groups that you want to share with, and the permissions that you want to grant them. You can choose from View, Edit, or Owner permissions.
Share with external applications: Share your saved search with external applications that can consume the data from Graylog. You can generate a URL that contains your query and its parameters, and copy it to your clipboard. You can then use this URL to access your search results from any application that supports HTTP requests, such as curl, wget, or Postman.

Saving and sharing searches, you can create reusable and collaborative searches, and integrate Graylog with other tools. But what if you want to visualize your log data in different ways? That’s where the next step comes in: creating dashboards.

3. Analyzing Logs in Graylog

Once you have found the logs that you are interested in, you may want to visualize them in different ways and gain more insights from your data. That’s where the next step comes in: analyzing logs in Graylog.

Analyzing logs in Graylog involves creating dashboards, adding widgets and visualizations, and configuring alerts and notifications. You can use these features to display your log data in various formats, such as charts, graphs, tables, maps, and more. You can also use these features to monitor your log data and get notified of important events, such as errors, anomalies, or trends.

To analyze your logs in Graylog, you will need to follow these steps:

Create a dashboard. A dashboard is a collection of widgets and visualizations that show the results of your queries in a single page. You can create multiple dashboards for different purposes and topics, and customize them according to your preferences.
Add widgets and visualizations to your dashboard. Widgets and visualizations are the elements that display your log data in different formats. You can add various types of widgets and visualizations to your dashboard, such as charts, graphs, tables, maps, and more. You can also configure the settings and options of each widget and visualization, such as the title, the query, the time range, the colors, and more.
Configure alerts and notifications for your dashboard. Alerts and notifications are the features that allow you to monitor your log data and get notified of important events. You can configure alerts and notifications for your dashboard, such as the conditions that trigger an alert, the actions that are performed when an alert is triggered, and the recipients that receive the notifications.

By analyzing your logs in Graylog, you can visualize your log data in different ways and gain more insights from your data. You can also monitor your log data and get notified of important events. But how do you create a dashboard, add widgets and visualizations, and configure alerts and notifications? That’s what we will cover in the next sections.

3.1. Creating Dashboards

Once you have found the logs that you are interested in, you can create dashboards to display them in a more visual and interactive way. Dashboards are collections of widgets and visualizations that show the results of your queries in different formats, such as charts, graphs, tables, maps, and more. You can use dashboards to monitor the trends and patterns of your log data, compare different metrics and dimensions, and explore the data in more depth.

To create a dashboard, follow these steps:

Go to the Dashboards page in the Graylog web interface.
Click the Create dashboard button in the top right corner.
Enter a title and a description for your dashboard. You can also select a time range for your dashboard, which will apply to all the widgets and visualizations that you add to it. You can use the same options as in the search bar to choose a predefined, custom, or relative time range.
Click the Create dashboard button to save your dashboard.

You will see your new dashboard in the main area of the page, with an empty canvas where you can add widgets and visualizations. You can also see the list of your existing dashboards in the left sidebar, where you can switch between them, edit them, or delete them.

Creating a dashboard is the first step to analyzing your logs in Graylog. But how do you add widgets and visualizations to your dashboard? And how do you customize them to suit your needs and preferences? That’s what you will learn in the next section: adding widgets and visualizations.

3.2. Adding Widgets and Visualizations

After creating a dashboard, you can add widgets and visualizations to it to display the results of your queries in different formats. Widgets and visualizations are graphical elements that show the data in various ways, such as charts, graphs, tables, maps, and more. You can use widgets and visualizations to monitor the trends and patterns of your log data, compare different metrics and dimensions, and explore the data in more depth.

To add a widget or a visualization to your dashboard, follow these steps:

Go to the dashboard that you want to edit and click the Edit button in the top right corner.
Click the Add widget button in the top left corner.
Select the type of widget or visualization that you want to add from the drop-down menu. You can choose from a variety of options, such as Count, Quick values, Chart, World map, and more.
Enter the query and the time range for your widget or visualization. You can use the same options as in the search bar to specify your search criteria and filter the results.
Configure the settings and options for your widget or visualization. Depending on the type of widget or visualization that you have chosen, you can customize different aspects of it, such as the title, the description, the fields, the colors, the layout, and more.
Click the Create button to save your widget or visualization and add it to your dashboard.

You will see your new widget or visualization in the main area of the dashboard, showing the data that matches your query and settings. You can drag and drop the widget or visualization to change its position, or resize it to change its dimensions. You can also edit or delete the widget or visualization by clicking the More actions button in the top right corner of it.

Adding widgets and visualizations to your dashboard, you can create a more visual and interactive way to display and analyze your log data. But what if you want to get notified when certain conditions are met or thresholds are exceeded? That’s where the next step comes in: configuring alerts and notifications.

3.3. Configuring Alerts and Notifications

Another way to analyze your logs in Graylog is to configure alerts and notifications. Alerts and notifications are a way to monitor your log data and get notified when certain conditions are met or thresholds are exceeded. You can use alerts and notifications to keep track of the status and performance of your systems, detect and respond to issues, and prevent potential problems.

To configure alerts and notifications, follow these steps:

Go to the Alerts page in the Graylog web interface.
Click the Manage conditions button in the top right corner.
Click the Add new condition button in the top left corner.
Select the type of condition that you want to create from the drop-down menu. You can choose from two types of conditions: Message count condition and Field content condition. A message count condition triggers an alert when the number of messages that match a query is above or below a certain threshold. A field content condition triggers an alert when a field of a message has a certain value or matches a certain pattern.
Enter the details and settings for your condition. Depending on the type of condition that you have chosen, you can specify different aspects of it, such as the title, the description, the query, the time range, the threshold, the field, the value, and more.
Click the Create condition button to save your condition.
Click the Manage notifications button in the top right corner.
Click the Add new notification button in the top left corner.
Select the type of notification that you want to create from the drop-down menu. You can choose from different types of notifications, such as Email notification, HTTP notification, Slack notification, and more.
Enter the details and settings for your notification. Depending on the type of notification that you have chosen, you can specify different aspects of it, such as the title, the description, the recipients, the URL, the channel, and more.
Click the Create notification button to save your notification.
Click the Manage alert rules button in the top right corner.
Click the Add new alert rule button in the top left corner.
Enter a title and a description for your alert rule.
Select the condition and the notification that you want to associate with your alert rule from the drop-down menus.
Click the Create alert rule button to save your alert rule.

You will see your new alert rule in the main area of the page, showing the condition and the notification that you have configured. You can also see the list of your existing alert rules in the left sidebar, where you can switch between them, edit them, or delete them.

Configuring alerts and notifications, you can create a more proactive and responsive way to monitor and analyze your log data. You can also use the Alerts overview page to see the history and status of your alerts, and the Alerts configuration page to adjust the general settings and options for your alerts.

You have learned how to search and analyze your logs in Graylog using the search bar, filters, operators, dashboards, widgets, visualizations, alerts, and notifications. But what are the benefits and challenges of using Graylog for log management and analysis? And what are some best practices and tips to get the most out of Graylog? That’s what you will learn in the final section: conclusion.

4. Conclusion

In this tutorial, you have learned how to search and analyze logs in Graylog using the search bar, filters, operators, dashboards, widgets, visualizations, alerts, and notifications. You have seen how Graylog can help you collect, store, and analyze logs from various sources, and how you can use its powerful features to find and visualize the information you need from your logs.

Graylog is a great tool for log management and analysis, as it offers many benefits, such as:

It is open source and free to use, with a large and active community of users and developers.
It is scalable and reliable, as it can handle large volumes of data and high availability requirements.
It is flexible and extensible, as it supports many types of data sources and formats, and allows you to create custom plugins and integrations.
It is user-friendly and intuitive, as it provides a web-based interface and a rich set of graphical elements to interact with your data.

However, Graylog also has some challenges and limitations, such as:

It requires some technical knowledge and skills to set up and configure, especially if you want to use advanced features and options.
It may not support some specific data sources or formats, or some specific analysis or visualization needs, without additional plugins or integrations.
It may not be compatible with some other tools or platforms that you use for log management and analysis, or may require additional steps or costs to integrate with them.

Therefore, before choosing Graylog as your log management and analysis tool, you should consider your own needs and preferences, and compare Graylog with other alternatives that are available in the market.

Some best practices and tips to get the most out of Graylog are:

Plan your log strategy and architecture before implementing Graylog, and define your goals and requirements for log collection, storage, and analysis.
Follow the official documentation and guides to install and configure Graylog, and use the community forums and resources to get help and support.
Use streams, fields, and filters to organize and filter your logs, and use operators and functions to refine your queries and calculations.
Use dashboards, widgets, and visualizations to display and explore your log data, and use alerts and notifications to monitor and react to your log data.
Use plugins and integrations to extend Graylog’s functionality and compatibility, and create your own plugins and integrations if needed.
Keep your Graylog server and plugins updated and secure, and backup your data regularly.

We hope you have enjoyed this tutorial and learned something useful from it. If you have any questions or feedback, please let us know in the comments section below. Thank you for reading and happy logging!

1. Introduction

2. Searching Logs in Graylog

2.1. Using the Search Bar

2.2. Applying Filters and Operators

2.3. Saving and Sharing Searches

3. Analyzing Logs in Graylog

3.1. Creating Dashboards

3.2. Adding Widgets and Visualizations

3.3. Configuring Alerts and Notifications

4. Conclusion

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Part 8: Conclusion and Best Practices

Part 7: Creating and Managing Alerts in Graylog

Part 6: Creating and Managing Dashboards in Graylog