Software · head to head
Azure Monitor vs Fluent Bit
The short version
- Each has a real cost: Azure Monitor billed per GB ingested across three separate log plans, Auxiliary, Basic and Analytics, so the plan chosen changes the rate as much as the volume does; Fluent Bit fluent Bit ships over 100 built in plugins against more than 1,000 external plugins available for Fluentd, so fewer integrations exist out of the box
- They diverge on capability: Azure Monitor covers Metrics collection, Fluent Bit covers Lightweight processing.
Where they differ
Only the attributes on which Azure Monitor and Fluent Bit actually diverge.
| Attribute | Azure Monitor | Fluent Bit |
|---|---|---|
| Pricing model | usage-based | open-source |
| Founded | 2010 | 2015 |
Identical on both: starting price (Free), free tier (Yes), platforms (Web, Api), user rating (Not yet rated), category (Unknown).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Azure Monitor
- Metrics collection
- Alerts and notifications
- Custom dashboards
Only in Fluent Bit
- Lightweight processing
- Data parsing
- Event filtering
Both cover
- Log collection
- API
- Webhooks
- REST
- Web support
- Api support
What people use each for
The jobs each tool is most often brought in to do.
Azure Monitor
- Collecting logs and metrics from Azure resourcesnot Fluent Bit
- Alerting on metric thresholds and log queriesnot Fluent Bit
- Application performance monitoring through Application Insightsnot Fluent Bit
- Long-term log retention for compliancenot Fluent Bit
- Querying operational data with KQLnot Fluent Bit
Fluent Bit
- Lightweight log and metric forwarding from containers and edge devicesnot Azure Monitor
- Kubernetes node level log collection with a small memory footprintnot Azure Monitor
- Filtering and enriching telemetry before shipping it to a backendnot Azure Monitor
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Azure Monitor
- Billed per GB ingested across three separate log plans, Auxiliary, Basic and Analytics, so the plan chosen changes the rate as much as the volume does
- Only the first 5 GB a month of Analytics logs is free per billing account
- Retention beyond the base period is charged per GB per month, up to 2 years interactive and 12 years long term
- Log queries and search jobs are billed per GB scanned, so investigating an incident costs money
- Alert rules are billed per time series for metrics and by execution frequency for logs
- The pricing page shows placeholders rather than rates until a region and currency are chosen
Fluent Bit
- Fluent Bit ships over 100 built in plugins against more than 1,000 external plugins available for Fluentd, so fewer integrations exist out of the box
- It is written in C, so extending it beyond the built in plugins means writing C rather than Ruby
- Dependencies are zero only until a plugin requires one
Pricing, plan by plan
Azure Monitor
Free- FreeFree
- Log collection
- Metrics collection
- Alerts and notifications
Fluent Bit
Free- FreeFree
- Log collection
- Lightweight processing
- Data parsing
Which should you pick?
Choose Azure Monitor if
- You need metrics collection.
- You want to start without paying.
- You work on Web, Api.
- You also want alerts and notifications.
Choose Fluent Bit if
- You need lightweight processing.
- You want to start without paying.
- You work on Web, Api.
- You also want data parsing.
Questions people ask
- Is Azure Monitor or Fluent Bit better?
- Neither clearly leads. Azure Monitor starts at Free and Fluent Bit at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Azure Monitor or Fluent Bit?
- Azure Monitor starts at Free and Fluent Bit at Free.
- Does Azure Monitor or Fluent Bit run on more platforms?
- Both run on Web, Api, so platform support will not decide this one for you.
- Can I use Azure Monitor for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Azure Monitor best used for?
- Azure Monitor is most often used for collecting logs and metrics from azure resources, alerting on metric thresholds and log queries, application performance monitoring through application insights, long-term log retention for compliance. Of those, collecting logs and metrics from azure resources and alerting on metric thresholds and log queries are not what Fluent Bit is typically brought in for.
- What can Azure Monitor do that Fluent Bit cannot?
- Azure Monitor covers Metrics collection, Alerts and notifications, Custom dashboards. Fluent Bit covers Lightweight processing, Data parsing, Event filtering. Both handle Log collection, API, Webhooks, REST.