Add support for xDS based EndpointGroup
#5450
Draft
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
jrhee17
force-pushed
the
poc/xds-endpoints
branch
from
2742286 to
4c52f26
Compare
ikhoon
reviewed
Feb 13, 2024
core/src/main/java/com/linecorp/armeria/client/endpoint/CompositeEndpointGroup.java
Outdated
Show resolved
Hide resolved
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #5450 +/- ##
============================================
+ Coverage 73.95% 74.18% +0.22%
- Complexity 20115 20996 +881
============================================
Files 1730 1821 +91
Lines 74161 77501 +3340
Branches 9465 9901 +436
============================================
+ Hits 54847 57492 +2645
- Misses 14837 15342 +505
- Partials 4477 4667 +190 ☔ View full report in Codecov by Sentry. |
jrhee17
force-pushed
the
poc/xds-endpoints
branch
from
d0d0ca2 to
62afe03
Compare
jrhee17
force-pushed
the
poc/xds-endpoints
branch
2 times, most recently
from
a320ce5 to
72788df
Compare
jrhee17
changed the title
XdsEndpointGroup to be a CompositeEndpointGroupEndpointGroup
jrhee17
force-pushed
the
poc/xds-endpoints
branch
2 times, most recently
from
43f442b to
66cde21
Compare
jrhee17
force-pushed
the
poc/xds-endpoints
branch
from
f2530e3 to
51367a0
Compare
This was referenced Mar 14, 2024
minwoox
pushed a commit
that referenced
this pull request
Mar 22, 2024
…5502) Motivation: More classes will be added related to client endpoint, so I propose that we move `XdsEndpointGroup` from the package `com.linecorp.armeria.xds` to `com.linecorp.armeria.xds.client.endpoint`. Although this PR is mostly refactoring, a new API `EndpointGroup#of(ClusterSnapshot)` is added since `ConfigSourceClient` uses `GrpcService` to decide on the endpoint which will be used. POC: #5450 Modifications: - Move `XdsEndpointGroup`, `XdsConstants` to `com.linecorp.armeria.xds.client.endpoint` - Introduce a new API `EndpointGroup#of(ClusterSnapshot)` - Introduce `XdsEndpointUtil` and move `client.endpoint` related utility methods from `XdsConverterUtil` Result: - Preparation for adding new features to `XdsEndpointGroup` is done <!-- Visit this URL to learn more about how to write a pull request description: https://armeria.dev/community/developer-guide#how-to-write-pull-request-description -->
minwoox
pushed a commit
that referenced
this pull request
Mar 22, 2024
…5501) Motivation: `EdfLoadBalancer` is a basic load balancer which distributes entries based on weight using [Earliest Deadline First Scheduling](https://en.wikipedia.org/wiki/Earliest_deadline_first_scheduling). ref: https://github.com/envoyproxy/envoy/blob/b7818b0df716af47ec22982c5a1cbbace5f2ae15/source/common/upstream/load_balancer_impl.h#L508 This is used not only for request load balancing, but also load balancing based on `Locality` ref: https://github.com/envoyproxy/envoy/blob/b7818b0df716af47ec22982c5a1cbbace5f2ae15/source/common/upstream/upstream_impl.cc#L625 Within our codebase, it seems like we could use `WeightedRandomDistributionEndpointSelector` easily for this purpose. I propose that we extract a `WeightedRandomDistributionSelector` and make it publicly available. See the following for a sample use-case in #5450 ref: https://github.com/line/armeria/blob/bd4968fda63089b2c309583b21201dff1a1119bf/xds/src/main/java/com/linecorp/armeria/xds/client/endpoint/HostSet.java#L38-L39 POC: #5450 Modifications: - Extract `WeightedRandomDistributionSelector` and move it to the `internal` package. Result: - `WeightedRandomDistributionSelector` is now ready to be reused. <!-- Visit this URL to learn more about how to write a pull request description: https://armeria.dev/community/developer-guide#how-to-write-pull-request-description -->
jrhee17
added a commit
that referenced
this pull request
Apr 2, 2024
…int pt 3) (#5503) This PR attempts to support `DNS`, Health Checked clusters. This is done by converting `ClusterSnapshot` to an `EndpointGroup` via `XdsEndpointUtil#convertEndpoints`. The rest of the changes are simply refactoring. Motivation: There are three major points of change: 1. `XdsEndpointUtil#convertEndpointGroup` has been introduced which converts a `ClusterSnapshot` into an `EndpointGroup`. This method essentially converts a `ClusterSnapshot` into a `DnsAddressEndpointGroup` or a `HealthCheckedEndpointGroup`. Note that only basic functionality is supported at this stage. During this implementation, I found it convenient to refer to a `LbEndpoint` or `LocalityLbEndpoints` for a particular `Endpoint`. For this reason, `XdsAttributeKeys`, `XdsAttributeAssigningEndpointGroup` has been introduced so that xDS resource information can be retrieved easily. This is useful later as well, in order to fetch the locality, priority, health, etc. of a particular endpoint. 2. New data structures have been introduced to match that of envoy's. Some include: - `LoadBalancer`: https://github.com/envoyproxy/envoy/blob/d5bfc06f110647127edc5ddc3bd6cfda78f2760b/source/common/upstream/load_balancer_impl.h#L83 - `ClusterManager`: https://github.com/envoyproxy/envoy/blob/d5bfc06f110647127edc5ddc3bd6cfda78f2760b/source/common/upstream/cluster_manager_impl.h#L245 - `ClusterEntry`: https://github.com/envoyproxy/envoy/blob/d5bfc06f110647127edc5ddc3bd6cfda78f2760b/source/common/upstream/cluster_manager_impl.h#L578 - `PrioritySet`: https://github.com/envoyproxy/envoy/blob/d5bfc06f110647127edc5ddc3bd6cfda78f2760b/envoy/upstream/upstream.h#L533 - `SubsetLoadBalancer`: https://github.com/envoyproxy/envoy/blob/d5bfc06f110647127edc5ddc3bd6cfda78f2760b/source/extensions/load_balancing_policies/subset/subset_lb.h#L135 The nuances are slightly different due to a difference in existing APIs, difference in threading model and lifecycles. However, an effort has been made to keep the implementation relatively similarly looking. Note that the logic inside `SubsetLoadBalancer` is changed minimally to keep the changeset small. 3. The way updates are propagated has changed for `XdsEndpointGroup`. `ClusterManager` now receives updates on the `ListenerSnapshot` by listening to the provided `ListenerRoot`. On each snapshot update, a `ClusterEntry` is created for each `ClusterSnapshot`. `ClusterEntry` constructs the `EndpointGroup` based on the provided `ClusterSnapshot` and endpoint updates (dns/health checked `EndpointGroup`s may update multiple times). Whenever 1) A `ClusterEntry#endpointGroup`'s endpoints are updated or 2) `ListenerSnapshot` is updated, then `ClusterManager#notifyListeners` calls `XdsEndpointGroup#setEndpoints`. This will eventually trigger `XdsEndpointSelector#selectNow`. This will subsequently trigger `ClusterManager#selectNow` and `LoadBalancer#selectNow`. **Miscellaneous changes** - `XdsEndpointGroup` implements `EndpointGroup` directly since custom comparison logic is required for `XdsEndpointGroup#updateState` - I think we will eventually need to turn `Endpoint` into an interface, and supported various types of endpoints (e.g. `HealthCheckedEndpoint`, `XdsEndpoint`, etc..). For now, I propose to use attributes for simplicity. - Because `ClusterManager#notifyListeners` is called for any update (i.e. update to the snapshot, `DnsAddressEndpointGroup` updates, etc..) there is a good chance that empty endpoints will be set. This isn't ideal based on the normal use case where users usually wait for initial endpoints via `EndpointGroup#whenComplete`. I've set `allowEmptyEndpoints = false` to be the default. POC: #5450 Modifications: - Introduce `XdsEndpointUtil#convertEndpointGroup`, which creates an `EndpointGroup` based on the `ClusterSnapshot`. `DNS`, `HealthCheck` capabilities are partially supported. - `LoadBalancer`, `ClusterManager`, `ClusterEntry`, `PrioritySet`, `SubsetLoadBalancer` are newly introduced. - `ClusterManager` listens for any updates regarding `Endpoint`s or `Snapshot`s and notifies `EndpointGroup` if there are any changes. Every time this occurs, `LoadBalancer#selectNow` is called. Result: - `XdsEndpointGroup` now partially supports DNS and health check. <!-- Visit this URL to learn more about how to write a pull request description: https://armeria.dev/community/developer-guide#how-to-write-pull-request-description --> --------- Co-authored-by: minux <[email protected]>
jrhee17
force-pushed
the
poc/xds-endpoints
branch
from
bd4968f to
a5d57a5
Compare
This was referenced Apr 15, 2024
minwoox
pushed a commit
that referenced
this pull request
Jun 10, 2024
Motivation: This pull request attempts to implement the default [EdfLoadBalancerBase](https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/load_balancer_impl.h#L508) which is the default load balancer used in envoy. Most load balancer implementations in envoy derive from this base class. The basic load balancer supports [locality weighted load balancing](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/locality_weight) and [priority levels](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/priority). Note that not all functionality (namely zone aware load balancing, etc..) have been implemented for simplicity. Additionally, [SubsetLoadBalancer](https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/extensions/load_balancing_policies/subset/subset_lb.h#L135) has not been implemented in this PR for easier reviewing. The previous `SubsetLoadBalancer` will be replaced in the next (and final) pull request. This pull request mostly focuses on updating the `LoadBalancer` state when a `ClusterSnapshot` is updated. The flow is as follows: 1. `ClusterEntry#accept` is called, which indicates a `ClusterSnapshot` has been updated 2. A [PriorityStateManager](https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/upstream_impl.h#L1347) computes endpoints per priority and locality. - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/upstream_impl.cc#L2075 3. A [PrioritySet](https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/envoy/upstream/upstream.h#L512) is created. This `PrioritySet` contains a map of `Integer -> HostSet` where a [HostSet](https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/envoy/upstream/upstream.h#L382) contains host information for each health/locality. - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/upstream_impl.cc#L2099 - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/upstream_impl.cc#L610 4. A `DefaultLbStateFactory` is created which creates a `LbState` for the `DefaultLoadBalancer`. A `LbState` is a convenience object used to avoid potential race conditions. The `LbState` is replaced atomically from the perspective of `DefaultLoadBalancer`. - In terms of `envoy` source, each load balancer registers a callback which listens for `HostSet` updates. Once a `HostSet` is updated, the load balancer state is updated. - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/load_balancer_impl.cc#L149-L154 - Essentially, a range from 1~100 is assigned to each priority where healthy endpoints are prioritized. 5. Lastly, the load balancer chooses a `HostSource`, and subsequently a host from the selected `HostSet` - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/load_balancer_impl.cc#L1173 - https://github.com/envoyproxy/envoy/blob/bdff856f461c2261305b8303285e83d6f2cec627/source/common/upstream/load_balancer_impl.cc#L891-L892 ref: #5450 Modifications: - `ClusterEntry` now creates a `PrioritySet` for each `ClusterSnapshot` update - In order to create a `PrioritySet`, utility classes `PriorityStateManager`, `PriorityState`, `HostSet`, `UpdateHostsParam` have been created. - Utility classes `EndpointUtil`, `EndpointGroupUtil` have been created - `DefaultLoadBalancer` has been introduced. The functionality of this `LoadBalancer` is equivalent to `EdfLoadBalancer`. - `DefaultLbStateFactory` has been introduced to facilitate creating a state for `DefaultLoadBalancer`. The `LbState` created by `DefaultLbStateFactory` is intended to be updated atomically from the perspective of `DefaultLoadBalancer`. Result: - Priority and locality based load balancing is now available for `XdsEndpointGroup` <!-- Visit this URL to learn more about how to write a pull request description: https://armeria.dev/community/developer-guide#how-to-write-pull-request-description -->
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Motivation:
Explain why you're making this change and what problem you're trying to solve.
Modifications:
Result: