Istio in Action

[keyolk]

https://learning.oreilly.com/library/view/istio-in-action/9781617295829/

patterns

• Client-side load balancing—Give the client the list of possible endpoints, and let it decide which one to call.
• Service discovery—A mechanism for finding the periodically updated list of healthy endpoints for a particular logical service.
• Circuit breaking—Shed load for a period of time to a service that appears to be misbehaving.
• Bulkheading—Limit client resource usage with explicit thresholds (connections, threads, sessions, and so on) when making calls to a service.
• Timeouts—Enforce time limitations on requests, sockets, liveness, and so on when making calls to a service.
• Retries—Retry a failed request.
• Retry budgets—Apply constraints to retries: that is, limit the number of retries in a given period (for example, only retry 50% of the calls in a 10-second window).
• Deadlines—Give requests context about how long a response may still be useful; if outside the deadline, disregard processing the request.

application libraries

• Hystrics, Ribbon, Eureka ...
• Language support
• Maintaining library

infrastructure

• application aware service proxy
  • mod_proxy, haproxy, nginx ...

envoy proxy

service mesh

• service resilience
• observability signals
• traffic control capabilities
• security
• policy enforcement

[keyolk]

control plane

• APIs for operators to specify desired routing/resilience behavior
• APIs for the data plane to consume their configuration
• A service discovery abstraction for the data plane
• APIs for specifying usage policies
• Certificate issuance and rotation
• Workload identity assignment
• Unified telemetry collection
• Service-proxy sidecar injection
• Specification of network boundaries and how to access them

istiod

• galley: configuration management
• citadel: tls, security
• pilot: envoy management, service discovery
  • xds provider

custom resrouces

• virtual service
• destination rule
• gateway
• sidecar
• service entry
• proxy config
• envoy filter
• workload entry
• worklaod group

[keyolk]

Envoy

supports

• openmetrics

• opentracing

• Extensibility with WebAssembly

• Open community

• Modular codebase built for maintenance and extension

• HTTP/2 support (upstream and downstream)

• Deep protocol metrics collection

• C++ / non-garbage-collected

• Dynamic configuration, no need for hot restarts

Dynamic configuration

• LDS
• DS
• CDS
• EDS
• SDS
• ADS