We're seeing quite a few former Airbrake users switch to Rollbar. Why are they doing that? We're glad you asked...
This article will cover a few key areas where we think Rollbar differentiates. It's kind of long, so feel free to skim. There's also a big comparison table at the end.
Reliability and Site Speed
We aren't regular Airbrake users ourselves, but a frequent refrain we see on Twitter and hear in conversations has been disatisfaction with Airbrake's uptime and site speed. We've taken this to heart and done a lot of work to make Rollbar reliable and fast. We're not perfect, but we're proud of the work we've done and it's paying off.
Reliability
Our team has built systems at scale (50M users, 200+ servers) before and we're applying what we've learned to make Rollbar rock-solid. Here are a few things to note:
- We aren't hosted on AWS or Heroku. We're currently in 6 different datacenters through Softlayer—Dallas, San Jose, Seattle, Washington DC, Singapore, and Amsterdam—using a mix of bare metal and cloud servers.
- The API tier is separate from the Web tier. It's on its own hardware, currently in 4 of our datacenters: Dallas, San Jose, Singapore, and Amsterdam. We use Anycast DNS to route traffic to the closest datacenter worldwide, and automatic failover in case of a local outage.
- The pipeline from the API to alerts and the dashboard is fully asynchronous. If our primary database goes down, payloads will queue up but won't be lost. API servers write to local files, which are loaded in the background to the 'raw' database. A separate system processes items in the raw database into the main database and enqueues alerts. Still other systems actually send the alerts and build the various summary views used through the interface.
- For the Web tier, we have redundant frontend load balancers in two datacenters in case of a public network outage, as well as multiple application servers in case of hardware issues.
- Each of our database layers (raw, main) is set up in a master-master setup allowing for fast failover. Nightly backups are taken off the passive master and stored in another datacenter.
- All of this is monitored extensively both internally (Nagios) and externally (Pingdom). Our status site shows the status as seen by Pingdom. At least one developer is on-call at all times.
Site Speed
The key to our current snappiness is in keeping everything in memory. The primary databases are each beefy boxes with 256gb RAM and terabytes of SSDs. Raw occurrence data is stored on regular disks and fronted by memcache.
We've instrumented the app and set alerts so we're notified whenever a request takes longer than 1 second to complete. It doesn't go off very often. We're not Google-fast, but we're pretty fast :)
If you have more questions about our infrastructure, please email us at team@rollbar.com. We're happy to answer questions and we'll share that knowledge here.
Logging things that aren't exceptions
Rollbar was built from the ground up to support general-purpose logging as well as the common special case of exception logging. This means:
- The key abstraction is called an "Item" (not very descriptive, we know), not an "Error"
- Items have a severity level, ranging from "debug" to "critical". This can be set in the API payload, and can be changed later in the interface.
- Occurrences (which are aggregated into Items) can have a 'trace' (if they're an exception) or a 'message' (if they're a generic log message).
- Notification preferences can be configured per-level. By default, we'll notify you about errors and criticals but not warnings or lower.
Want to record a non-exception warning condition, like not being able to connect to an external API? Rollbar.warning("Could not connect to Acme API.", :some_data => @its_value). Have an exception that you want to keep an eye on, but isn't really an error? Mark it as a Warning in the interface.
If you're familiar with logging frameworks, you'll feel right at home here. We use this ourselves for everything from logging business events ("user logged in") to form validation errors to slow queries.
Search
Want to find exceptions that occurred in a particular file? In a date range? Warnings on a particular host? That contain the word "hello"? Rollbar can do all of this and more.
The search index is updated in real-time and runs on the fantastic Sphinx Search.
Graphs Everywhere
Debugging complex issues is often about finding patterns, and often the best way to see that is visually. The Rollbar dashboard includes graphs of occurrence and new item counts, with deploys overlayed (so you can see how deploys affect error rates). There are also inline graphs (sparklines) showing the rates of each individual item on the Dashboard and Search pages.
On the Item Detail page, there are graphs of occurrence counts by hour and day (again with deploys overlayed), a table of you can scan for patterns, and graphs showing the Browser and OS breakdowns.
A few cool features
Replays
If an error happened on a GET request, we have a Replay button that will re-run the same request (URL, headers, cookies and all) so you can instantly reproduce it.
Person Tracking
Airbrake has the basics here (recording which user was affected by a particular error), but Rollbar takes it to the next level. You can see the history of events seen by each user, as well as a list of all your users we have any data for.
One customer we know of is using this for debugging complex JavaScript issues—they use Rollbar.debug to log debug messages, and then view the results in the Rollbar interface.
Flexible notification rules
You can set up notification rules for any of our supported channels (see the list in the table below), filtered by environment, severity level, string match on the exception class+message, and string match on any of the filenames in the traceback.
Comparison Table
If you were looking for a big comparison table, this is for you:
| Rollbar | Airbrake | |
|---|---|---|
| Basics | ||
| Hosting provider | Softlayer (6 datacenters) | Rackspace |
| Data model | Exceptions and log messages | Exceptions only |
| SSL | ✓ | Paid plans only |
| Pricing model | Per-occurrence; optional rate limit | Pick a rate limit |
| On-premises available | ✓ | ❌ |
| Rate limits | Configurable per access token | Set by plan |
| Users | Unlimited | Varies by plan |
| Projects | Unlimited | Varies by plan |
| Teams | Unlimited | ❌ |
| Official Libraries | ||
| Ruby / Rails | ✓ | ✓ |
| Python / Django | ✓ | ❌ |
| PHP | ✓ | ❌ |
| Node.js | ✓ | ❌ |
| JavaScript | ✓ | ✓ |
| Flash | ✓ | ❌ |
| iOS | Beta | ✓ |
| Android | Beta | ✓ |
| Managing Errors | ||
| Severity levels | ✓ | ❌ |
| Auto-resolve old items | ✓ | ❌ |
| "Resolved" state | ✓ | ✓ |
| "Muted" state | ✓ | ❌ |
| Batch actions (set status, level) | ✓ | ✓ |
| Resolve from the item list | ✓ | ❌ |
| Finding Errors | ||
| Dashboard with reports and graphs | ✓ | ❌ |
| Search by status | ✓ | ✓ |
| Search by date, level | ✓ | ❌ |
| Search by title, hostname, context | ✓ | ❌ |
| Daily summary emails | ✓ | ❌ |
| Understanding Errors | ||
| Affected user counts | ✓ | ❌ |
| Graphs of rate over time | ✓ | ❌ |
| Browser and OS graphs | ✓ | ❌ |
| Table of occurrences by parameter | ✓ | ❌ |
| Basic person tracking | ✓ | ✓ |
| History by person | ✓ | ❌ |
| Replay button | ✓ | ❌ |
| Non-project code optionally hidden in stack traces | ✓ | ✓ |
| Collaboration | ||
| Comments on items | ✓ | ✓ |
| @-mentions in comments | ✓ | ❌ |
| Deploy Tracking | ||
| Record when you've deployed | ✓ | ✓ |
| Auto-resolve items on deploy | ✓ | ✓ |
| History of deploys and commits in each | ✓ | ❌ |
| GitHub Integration | ||
| Link from stack traces to file in GitHub | ✓ | ✓ |
| Available GitHub sign-in and project sync | ✓ | ❌ |
| Deploy history includes code commits | ✓ | ❌ |
| "Suspect Deploy" analysis | ✓ | ❌ |
| Notification Channels | ||
| ✓ | ✓ | |
| Asana | ✓ | ❌ |
| Campfire | ✓ | ✓ |
| Flowdock | ✓ | ✓ |
| GitHub Issues | ✓ | ✓ |
| HipChat | ✓ | ✓ |
| Lighthouse | ❌ | ✓ |
| JIRA | ✓ | ✓ |
| PagerDuty | ✓ | ❌ |
| Pivotal Tracker | ✓ | ✓ |
| Slack | ✓ | ❌ |
| Sprintly | ✓ | ❌ |
| Trello | ✓ | ❌ |
| Webhook | ✓ | ✓ |
| Miscellaneous | ||
| Free trial | ✓ | ✓ |
| Team-based permissions | ✓ | ❌ |
| RSS feed | ❌ | ✓ |
We tried to be as unbiased as possible, but if any of the above is inaccurate, please let us know: team@rollbar.com