Improving instance stability with rate limiting

When automated integrations or scripts send requests to Bamboo in huge bursts, it can affect Bamboo's stability, leading to drops in performance or even downtime. With rate limiting, you can control how many external REST API requests automations and users can make and how often they can make them, making sure that your Bamboo instance remains stable.

Rate limiting is incompatible with Oracle JDBC driver versions earlier than 21.x. If you're using or plan to use Bamboo with Oracle Database, make sure to install or upgrade to Oracle JDBC version 21.x or later. For more information, see Failed to enable rate limiting in Bamboo in the Bamboo Knowledge Base.

How rate limiting works

Here’s some details about how rate limiting works in Bamboo.

Limited requests

Rate limiting targets only external REST API requests, which means that requests made within Bamboo aren’t limited in any way. When users move around the Bamboo user interface, viewing projects, transitioning issues, and completing other actions, they won’t be affected by rate limiting, as we’re seeing this as a regular user experience that shouldn’t be limited.

Let’s use an example to better illustrate this:

  • When a user views an issue in Bamboo, a number of requests are sent in the background — these requests ask Bambo for comments, assignees, attachments, etc. Since this traffic is internal to Bamboo, it won’t be limited.

  • When the same user opens up the terminal on their laptop and sends a request to get information about an issue, it will be rate limited because it’s made outside of Bamboo.

Authentication mechanisms

To give you more details on how we recognize which requests should be limited, we’re targeting external HTTP requests with these authentication mechanisms:

  • Basic auth
  • OAuth
  • JSESSIONID cookie
Rate limiting technique we've chosen

Out of the many available techniques for enforcing rate limits, we’ve chosen to use token bucket, which gives users a balance of tokens that can be exchanged for requests. Here’s a summary of how it works:

  • Users are given tokens that are exchanged for requests. One token equals one request.

  • Users get new tokens at a constant rate so they can keep making new requests. This is their Requests allowed, and can be, for example, 10 every 1 minute.

  • Tokens are added to a user’s personal bucket until it’s full. This is their Max requests and allows them to adjust the usage of tokens to their own frequency, for example 20 every 2 minutes instead of 10 every 1 minute, as specified in their usual rate.

  • When a user tries to send more requests than the number of tokens they have, only requests that can draw tokens from the bucket will be successful. The remaining ones will end in a 429 error message (too many requests). The user can retry those requests once they get new tokens.

Integration with other Atlassian products

Bamboo works best when used with our other products like Bitbucket, or Jira. Technically, products like these are external to Bamboo, so they should be limited. In this case, however, we’re treating them as belonging to the same user experience and don’t want to enforce any limits for requests coming from or to these products.

The way it is now:

  • Data Center: Not limited in any way.

  • Cloud: There’s a known issue that applies rate limits to requests coming from/to cloud products. We’re working hard to disable rate limits for cloud products and should make that happen soon. For now, you can use a workaround. For more info, see Removing rate limits for Atlassian cloud products.

Apps from Atlassian Marketplace

The general assumption is that Marketplace apps are installed on a Bamboo instance, make internal requests from within Bamboo, and shouldn’t be limited. But, as always, it depends on how an app works.

  • Internal: If an app in fact works internally, enhancing the user experience, it won’t be limited. An example of such app would be a special banner that’s displayed on a Scrum board. Let’s say this banner checks all issues that were done and shows this sprint’s winner — a user who’s completed the most issues in this sprint. Traffic like that would be internal, not limited.

  • External: Apps whose requests are external to Bamboo are limited. Let’s say we have an app that displays a wallboard on TV. It asks Bamboo for details about boards, issues, assignees, etc. and then reshuffles and displays them in its own way as the earlier mentioned wallboard. An app like that sends external requests and behaves just like a user sending requests over a terminal.

It really depends on the app, but we’re assuming most of them shouldn’t be limited.

How rate limiting works in a cluster

Rate limiting is available for Data Center, so you most likely have a cluster of nodes behind a load balancer. You should know that each of your users will have a separate limit on each node (rate limits are applied per node, not per cluster).

In other words, if they have used their Requests allowed on one node and were rate limited, they could theoretically send requests again if they started a new session on a different node. Switching between the nodes isn’t something users can do, but keep in mind that this can happen.

Whatever limit you’ve chosen (e.g. 100 requests every 1 hour), the same limit will apply to each node, you don’t have to set it separately. This means that each user’s ability to send requests will still be limited, and Bamboo will remain stable regardless of which node their requests are routed to.

What limit should I choose?

Setting the right limit depends on many factors, so we can’t give you a simple answer. We have some suggestions, though.

Finding the right limit

The first step is to understand the size of traffic that your instance receives. You can do this by parsing the access log and finding a user than made the most REST requests over a day. Since UI traffic is not rate limited, this number will be higher than what you need as your rate limit. Now, that’s a base number — you need to modify it further based on the following questions:

  1. Can you afford to interrupt your users’ work? If your users’ integrations are mission-critical, consider upgrading your hardware instead. The more critical the integrations, the higher the limit should be — consider multiplying the number you found by two or three.

  2. Is your instance already experiencing problems due to the amount of REST traffic? If yes, then choose a limit that’s close to the base number you found on a day when the instance didn’t struggle. And if you’re not experiencing significant problems, consider adding an extra 50% to the base number — this shouldn’t interrupt your users and you still keep some capacity.

In general, the limit you choose should keep your instance safe, not control individual users. Rate limiting is more about protecting Bamboo from integrations and scripts going haywire, rather than stoping users from getting their work done.

How to turn on rate limiting

You need to be a Bamboo Administrator to turn on rate limiting.

To turn on rate limiting:

  1. Go to Administration > System > Rate limiting.

  2. Change the status to Enabled.

  3. Select one of the options: Allow unlimited requests, Block all requests, or Limit requests. The first and second are all about allowlisting and blocklisting. For the last option, you’ll need to enter actual limits. You can read more about them below.

  4. Click Save.

  5. Make sure to add exemptions for users who really need those extra requests, especially if you’ve chosen allowlisting or blocklisting. See Adding exemptions.

Limiting request — what it’s all about

As much as allowlisting and blocklisting shouldn’t require additional explanation, you’ll probably be using the Limit requests option quite often, either as a global setting or in exemptions.

Rate limiting page in the Jira admin console, with annotations explained below the image.

Let’s have a closer look at this option and how it works:

  1. Requests allowed: Every user is allowed a certain amount of requests in a chosen time interval. It can be 10 requests every second, 100 requests every hour, or any other configuration you choose.

  2. Max requests (advanced): Allowed requests, if not sent frequently, can be accumulated up to a set maximum per user. This option allows users to make requests at a different frequency than their usual rate (for example, 20 every 2 minutes instead of 10 every 1 minute, as specified in their rate), or accumulate more requests over time and send them in a single burst, if that’s what they need. Too advanced? Just make it equal to Requests allowed, and forget about this field — nothing more will be accumulated.

Examples

Example 1: Setting Requests allowed to 10 per hour, and Max requests to 100

Requests allowed: 10/hour | Max requests: 100

  • One of the developers is sending requests on a regular basis, 10 per hour, throughout the day. If they try sending 20 requests in a single burst, only 10 of them will be successful. They could retry the remaining 10 in the next hour when they’re allowed new requests.

  • Another developer hasn’t sent any requests for the past 10 hours, so their allowed requests kept accumulating until they reached 100, which is the max requests they can have. They can now send a burst of 100 requests and all of them will be successful. Once they used up all available requests, they have to wait for another hour, and they’ll only get the allowed 10 requests.

  • If this same developer sent only 50 out of their 100 requests, they could send another 50 right away, or start accumulating again in the next hour.

Example 1: Setting Requests allowed to 1 per second, and Max requests to 60

Requests allowed: 1/second | Max requests: 60

  • A developer can choose to send 1 request every second or 60 requests every minute (at any frequency).

  • Since they can use the available 60 requests at any frequency, they can also send all of them at once or in very short intervals. In such a case, they would be exceeding their usual rate of 1 request per second.

Finding the right limit

What limit should I choose?

Setting the right limit depends on many factors, so we can’t give you a simple answer. We have some suggestions, though.

Finding the right limit

The first step is to understand the size of traffic that your instance receives. You can do this by parsing the access log and finding a user than made the most REST requests over a day. Since UI traffic is not rate limited, this number will be higher than what you need as your rate limit. Now, that’s a base number — you need to modify it further based on the following questions:

  1. Can you afford to interrupt your users’ work? If your users’ integrations are mission-critical, consider upgrading your hardware instead. The more critical the integrations, the higher the limit should be — consider multiplying the number you found by two or three.

  2. Is your instance already experiencing problems due to the amount of REST traffic? If yes, then choose a limit that’s close to the base number you found on a day when the instance didn’t struggle. And if you’re not experiencing significant problems, consider adding an extra 50% to the base number — this shouldn’t interrupt your users and you still keep some capacity.

In general, the limit you choose should keep your instance safe, not control individual users. Rate limiting is more about protecting Bamboo from integrations and scripts going haywire, rather than stoping users from getting their work done.

Adding exemptions

Exemptions are, well, special limits for users who really need to make more requests than others. Any exemptions you choose will take precedence over global settings.

tip/resting Created with Sketch.

After adding or editing an exemption, you’ll see the changes right away, but it takes up to 1 minute to apply the new settings to a user.

Exemptions tab, with users exempted from rate limiting.

To add an exemption:

  1. Open the Exemptions tab.

  2. Click Add exemption.

  3. Find the user and choose their new settings.

    • You can’t choose groups, but you can select multiple users.

    • The options available here are just the same as in global settings: Allow unlimited requests, Block all requests, or assign custom limit.

  4. Click Save.

If you want to edit an exemption later, just click Edit next to a user’s name in the Exemptions tab.

Recommended: Add an exemption for anonymous access

Bamboo sees all anonymous traffic as made by one user: Anonymous. If your rate limits are not too high, it might happen that a single user drains the limit assigned to anonymous. It’s a good idea to add an exemption for this account with a higher limit, and then observe whether you need to increase it further. 

Identifying users who have been rate limited

When a user is rate limited, they’ll know immediately as they’ll receive an HTTP 429 error message (too many requests). You can identify users that have been rate limited by opening the List of limited accounts tab on the rate limiting settings page. The list shows all users from the whole cluster.

tip/resting Created with Sketch.

When a user is rate limited, it takes up to 5 minutes to show it in the table.

List of limited accounts.

Unusual accounts

You’ll recognize the users shown on the list by their name. It might happen, though, that the list will show some unusual accounts, so here’s what they mean:

  • Unknown: That’s a user that has been deleted in Bamboo. They shouldn’t appear on the list for more than 24 hours (as they can’t be rate limited anymore), but you might see them in the list of exemptions. Just delete any settings for them, they don’t need rate limiting anymore.

  • Anonymous: This entry gathers all requests that weren’t made from an authenticated account. Since one user can easily use the limit for anonymous access, it might be a good idea to add an exemption for anonymous traffic and give it a higher limit.

Adding limited requests to the log file

You can also view information about rate limited users and requests in the Bamboo log file. This is useful if you want to get more details about the URLs that requests targeted or originated from.

Show me how to do this...

To add limited requests to the log file:

  1. Go to Administration > System > Logging and profiling.

  2. Click Configure logging level for another package.

  3. Set the package name to: 

    com.atlassian.ratelimiting.internal.requesthandler.logging
  4. Set the logging level to DEBUG, and click Add.

  5. Every rate limited requests will now appear in the Bamboo log file.

Getting rate limited — user’s perspective

When users make authenticated requests, they’ll see rate limiting headers in the response. These headers are added to every response, not just when you’re rate limited.

HeaderDescription

X-RateLimit-Limit

The max. number of requests (tokens) you can ever have. New tokens won’t be added to your bucket after reaching this limit. Your admin configures this as Max requests.

X-RateLimit-Remaining

The remaining number of tokens. This is what you have and can use right now.

X-RateLimit-Interval-Seconds

The time interval in seconds. You get a batch of new tokens every such time interval.

X-RateLimit-FillRate

The number of tokens you get every time interval. Your admin configures this as Requests allowed.

retry-after

How long you need to wait until you get new tokens.

When you’re rate limited and your request doesn’t go through, you’ll see the HTTP 429 error message (too many requests). You can use these headers to adjust scripts and automations to your limits, making them send requests at a reasonable frequency.

Allowlisting URLs and external applications

Allowlisting URLs and resources

We’ve also added a way to allowlist whole URLs and resources on your Bamboo instance. This should be used as quick fix for something that gets rate limited, but shouldn’t.

When to use it?

For example, a Marketplace app added some new API to Bamboo. The app itself is used from the UI, so it shouldn’t be limited, but it might happen that Bamboo sees this traffic as external and applies the rate limit. In this case, you could disable the app or increase the rate limit, but this brings additional complications.

To work around issues like that, you can allowlist the whole resource added by the app so it works without any limits.

To add URLs the allowlist, configure -Dcom.atlassian.ratelimiting.whitelisted-url-patterns as a system property with the URLs in a comma-separated list. For example:

-Dcom.atlassian.ratelimiting.whitelisted-url-patterns=/**/rest/applinks/**,/**/rest/capabilities,/**/rest/someapi

For more info on setting system properties, see Configuring your system properties.

For more info on how to create URL patterns, see AntPathMatcher: URL patterns.

Allowlisting external applications

You can also allowlist consumer keys, which lets you remove rate limits for external applications integrated through AppLinks.

Find your app's consumer key

To find your app's consumer key:

  1. Go to  > Overview.

  2. In the left menu, scroll down to Manage apps and select Application links.

  3. Open Incoming authentication and copy the consumer key.

Add the consumer key to the allowlist

To add consumer keys to the allowlist, configure -Dcom.atlassian.ratelimiting.whitelisted-oauth-consumers as a system property with the consumer keys in a comma-separated list.

After entering the consumer key, the traffic coming from the related application will no longer be limited.

Adjusting your code for rate limiting

We’ve created a set of strategies you can apply in your code (scripts, integrations, apps) so it works with rate limits, whatever they are. For more info, see Adjusting your code for rate limiting.

Last modified on Feb 1, 2024

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