OpenFeature: The Future of Feature Flags

Transcript

1. OpenFeature The Future of Feature Flags
2. • • Software Engineer & Dev Advocate at Dynatrace • Writing code & talking about writing code • I attended a sewing course once Who Am I?
3. To Do List
4. To Do List v2
22. Canary • Testing in production • Can be lower cost • Quickly catch on to any issues
23. Choosing who gets what
25. “Feature flags are a software development technique that allows teams to enable, disable or change the behavior of certain features or code paths in a product or service, without modifying the source code.” - From the OpenFeature website
26. To Do List + Clear Completed Feature
28. The ENV_VAR swamp 0 Dynamic configuration 1 Dynamic evaluation 2 Operationalized feature-flags 3 FEATURE FLAG MATURITY MODEL
29. Dynamic Evaluation • Feature flag value is determined dynamically • Based on contextual information • Flag evaluation logic is centralized • Flag evaluation logic is independent of application
30. Dynamic Evaluation • No more if customer in legacyCustomers • Reduced blast radius • Experimentation that doesn’t require developer intervention • Compliance agility
31. Feature Flag Architecture
32. “is an open specification that provides a vendor-agnostic, community-driven API for feature flagging that works with your favorite feature flag management tool or in-house solution.” - From the OpenFeature website
33. Feature Flag Architecture
34. Dynamic Evaluation: evaluation context
35. Dynamic Evaluation: implicit evaluation context
36. OK, so we have the contextual data, but what do we do with it? Targeting: “The application of rules, specific user overrides, or fractional evaluations in feature flag resolution.” Dynamic Evaluation: How do we use the data?
37. Dynamic Evaluation: How do we use the data?
38. Dynamic Evaluation: How do we use the data?
39. Dynamic Evaluation: How do we use the data?
40. 1. flagd is OpenFeature’s cloud-native reference implementation of a feature-flag provider a. Written in Go b. Easily containerized c. Can source flags from various syncs (files, HTTP endpoints, Kubernetes CRDs) 2. Flags and targeting defined as JSON and a custom flag evaluation DSL build on JSONLogic Dynamic Evaluation: flagd
41. Dynamic Evaluation: flagd 1. “enable-mainframe-access” flag is a simple boolean flag with true/false variants 2. By default, it returns false (“off” variant) 3. Has a targeting rule that returns “on” variant if email address supplied in context ends with “@ingen.com” 4. Let’s check it out in the playground
42. In the context of feature flagging, dynamic evaluation means feature flags are evaluated during runtime, and use contextual data as the basis for their resolved flag values. Dynamic Evaluation
43. The ENV_VAR swamp 0 Dynamic configuration 1 Dynamic evaluation 2 Operationalized feature-flags 3 FEATURE FLAG MATURITY MODEL
44. A collection of APIs and SDKs used to collect telemetry data in a vendor agnostic way.
45. Basic Telemetry Types Traces Events (Logs) Metrics
46. Events (Logs) • A point in time without duration • Allow for arbitrary data and data types • Logs are a particular type of event
47. Traces • Collection of related spans ◦ Operation with a duration and timestamp • Arbitrary data stored as attributes • Spans linked together in a tree • Essentially 2 events - Start and End Time Spans
48. Metrics • Numeric data aggregated from a series of events • Usually original events are dropped • Usually attributes are more restricted • Requires keeping state on the client • Possible to generate later from events or traces
49. Sneaker shop architecture
50. Scenario Response times are reasonable
51. Scenario As load increases…. response time become worse.
52. Drilling into a trace The database is the culprit.
53. The DB is the bottleneck
54. Let’s add read replicas
55. Here’s the plan Put access to the read replica behind a feature flag 1 2 3 4 5 Enable the read replica for a small number of users Analyze the impact Enable the read replica for everyone Remove the feature flag
56. Adding the feature flag Identifies the feature flag Controls the database connection Evaluation context
57. Collect telemetry Monitors flag evaluations with OpenTelemetry events
58. Enabling feature Matching flag key Enabling for 25% of sessions
59. Starting the rollout Uh no! That shouldn’t happen.
60. That was close… Back to normal.
61. Failure rate by flag variant It only failed when the read replica was enabled. It only failed when the read replica was enabled.
62. Aggregate error messages Something is wrong with node 3
63. Let’s try that again…
64. Phase: Read replica disabled
65. Phase: Read replica enabled for 25%
66. Phase: Read replica enabled for 50%
67. Phase: Read replica enabled for 75%
68. Phase: Read replica enabled
69. Recap Rolled out an important performance fix 1 2 3 4 5 Controlled the impact of unforeseen problems Validated assumptions Rolled the new feature out for all users Continuously monitor impact
70. Thanks! Questions?