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Table of Contents

Status

Current state: Under discussionAccepted - 2.6.0 contains describe and alter functionality, resolve is pending for a future release.

Discussion thread: here

JIRA: KAFKA-7740

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

Quota management via Admin Client has gone through a couple drafts of proposals (KIP-248, KIP-422). While improvements have been made to the Admin interface for configuration handling, fitting quotas into the API is awkward as they don't fit the natural key-value pairing, nor is the configuration output expressive enough to return all useful information. Therefore, it'd be beneficial to have a quota-native API for managing quotas, which would offer an intuitive and less error-prone interface, convey additional information beyond what the configuration APIs provide, and enable for future extensibility as quotas types are added or evolved.

Background

By default, quotas are defined in terms of a user and client ID, where the user acts as an opaque principal name, and the client ID as a generic group identifier. When setting quotas, an administrator has flexibility in how it specifies the user and client ID for which the quota applies, where the user and client ID may be specifically named, indicated as a default, or omitted entirely. Since quotas have flexible configurations, there is a method for resolving the quotas that apply to a request: a hierarchy structure is used, where the most specific defined quota will be matched to a request's user and client ID.

...

As such, reasoning around quotas can be complex, as it's not immediately obvious which quotas may apply to a given user and/or client ID. Providing descriptive information about how quotas are matched is the first goal of this KIP. Likewise, retrieving and modifying quota values can be done in a more expressive and robust way, which is the second goal of the KIP.

APIs

In order to clearly specify the APIs, let's first disambiguate some terminology: Every client request that is processed is associated with a quota entity, which is a map of entity types to their corresponding entity names for the request. Using the current entity types, an entity is of the form {user=test-user, client-id=test-client}, where user and client-id are the types, and test-user and test-client are the names. However, when specifying a quota configuration entry, only a subset of the entity types need to be provided, which is referred to as an entity match, for example, {user=<default>}.

...

The quota values are of type Double, which presents a complication in that the RPC protocol doesn't support floating point values. To account for accommodate this, Double values will be serialized RPC protocol message type 'double' will be added, which will serialize doubles according to the IEEE 754 floating-point "double format" bit layout in their respective field. In Java, this can be done via Double.doubleToRawLongBits() and back via Double.longBitsToDouble(), which should easily translatable to other languages so portability is not a concern. In a future KIP (KIP-568), it will be proposed to add 'double' values natively to Kafka's RPC message type set.

Types Rationale

.

Types Rationale

While there's two defined entity types in AK, a server-side plugin mechanism allows for further expansion. Likewise, as use cases evolve, finer-grained quota control may be necessary. Therefore, entity types should not be While there's two defined entity types in AK, a server-side plugin mechanism allows for further expansion. Likewise, as use cases evolve, finer-grained quota control may be necessary. Therefore, entity types should not be statically bound to publicly defined constants, and instead the API should support flexible entity types by interpreting them as a String identifier. Any entity types that the broker doesn't understand should throw an IllegalArgumentException back to the client.

...

Since a fixed set of entity types aren't defined, an entity should be represented by a Map<String, String>, which maps an entity type to the entity name.

Public Interfaces

Admin client calls will be added to correspond to DescribeClientQuotas, ResolveClientQuotas, and AlterClientQuotas, with supporting types defined in the common.quotas package.

Common types in package org.apache.kafka.common.quota

...

(2.6.0)

Code Block
languagejava
/**
 * Describes a fully-qualified entity.client quota entity, which is a mapping of entity types to their names.
 */
public class QuotaEntityClientQuotaEntity {

    /**
     * The Typetype of an entity entry.
     */
    public static final String USER = "user";
    public static final String CLIENT_ID = "client-id";

    /**
     * RepresentsConstructs thea defaultquota nameentity for the given antypes entity,and inames.e. If thea entityname that's matchedis null,
     * when an exact match isn't found then it is mapped to the built-in default entity name.
     */
    public static* final@param String QUOTA_ENTITY_NAME_DEFAULT = // implementation defined

    /**entries maps entity type to its name
     */
 `entries` describes the fully-qualified entity. The key is a {@code Type} string, howeverpublic ClientQuotaEntity(Map<String, String> entries);

    /**
     * there@return maymap alsoof existentity keystype thatto areits notname
 enumerated by {@code Type} that*/
 still apply, e.g.
 public Map<String, String> entries();
}

/**
 * the server may internally associate another type. When querying entities, it's necessaryDescribes a component for applying a client quota filter.
 */
public class ClientQuotaFilterComponent {

    /**
 * to return all quota* typesConstructs becauseand quotareturns valuesa forfilter thesecomponent typesthat mayexactly influencematches the provided resolvedentity
     * quotaname value.for However,the whenentity alteringtype.
 a quota, any types that*
 aren't specified must be able
* @param entityType the entity *type to be inferred bythe filter component applies to
     * @param entityName the server,entity otherwisename anthat's error is returned.matched exactly
     */
    public static *ClientQuotaFilterComponent ForofEntity(String exampleentityType, {("CLIENT_ID" -> "test-client"),String entityName);

     /**
     * Constructs and returns a filter component that matches the  ("USER" -> "test-user"),built-in default entity name
     * for the entity type.
     *
     * @param entityType the  ("GROUP" -> "internal-group")}.entity type the filter component applies to
     */
    public static ClientQuotaFilterComponent QuotaEntityofDefaultEntity(Map<String, String> entriesString entityType);
}

    /**
     * DescribesConstructs aand quotareturns entitya filter.
 */
public class QuotaFilter {
    /** component that matches any specified name for the
     * A filter to be appliedentity type.
     *
     * @param entityType the entity type the filter component applies to
     */
 @param match the non-nullpublic stringstatic that's matched exactly
     */
    public QuotaFilterClientQuotaFilterComponent ofEntityType(String entityType, String match);
}

DescribeClientQuotas:

Code Block
languagejava
public class DescribeClientQuotasOptions extends AbstractOptions<DescribeClientQuotasOptions> { /**
    // Empty.
}

/**
 *@return Thethe resultcomponent's ofentity thetype
 {@link Admin#DescribeClientQuotas(Collection<QuotaFilter>, DescribeClientQuotasOptions)} call.
 */
    public class DescribeClientQuotasResult {String entityType();

    /**
     * Maps an entity to its configured quota value(s). Note if no value is defined for a quota@return the optional match string, where:
     *         if present, the name that's matched exactly
     * type for that entity's config, then it is notif includedempty, inmatches the resulting value map.default name
     *
     * @param entities the collection ofif entitiesnull, thatmatches matchedany thespecified filtername
     */
    public DescribeClientQuotasResult(KafkaFuture<Map<QuotaEntity, Map<String, Double>>> entities);

    Optional<String> match();
}

/**
 * Describes a client quota entity filter.
 */
public class ReturnsClientQuotaFilter a{

 map from quota entity/**
 to a future which can* beA usedfilter to checkbe theapplied statusto ofmatching theclient operationquotas.
     */
    public KafkaFuture<Map<QuotaEntity,* Map<String,@param Double>>> entities();
}

public interface Admin extends AutoCloseable {components the components to filter on
    ...

 * @param strict /**
whether the filter only includes *specified Describescomponents
 all entities matching all provided*/
 filters (logical AND) thatprivate have at least oneClientQuotaFilter(Collection<ClientQuotaFilterComponent> components, boolean strict);

     * quota value defined./**
     *
 Constructs and returns a *quota @paramfilter filtersthat filtersmatches toall applyprovided tocomponents. matchingMatching entities
     * @paramwith optionsentity thetypes optionsthat toare use
not specified by a component *will @returnalso resultbe containingincluded allin matchingthe entitiesresult.
     */
    DescribeClientQuotasResult describeClientQuotas(Collection<QuotaFilter> filters, DescribeClientQuotasOptions options);
}

ResolveClientQuotas:

Code Block
languagejava
public class ResolveClientQuotasOptions extends AbstractOptions<ResolveClientQuotasOptions> {* @param components the components for the filter
    // Empty.
}

/** */
 * The result ofpublic thestatic {@linkClientQuotaFilter Admin#ResolveClientQuotascontains(Collection<QuotaEntity>,Collection<ClientQuotaFilterComponent> ResolveClientQuotasOptions)} call.
 */
public class ResolveClientQuotasResult {components);

    /**
     * InformationConstructs and aboutreturns a specific quota configurationfilter entry.
that matches all provided components. */
    public class Entry {Matching entities
     * with entity /**
types that are not specified by a component will *not* @parambe source the entity source forincluded in the valueresult.
     *
     * @param valuecomponents the non-null value
    components for the filter
     */
    public static ClientQuotaFilter  public Entry(QuotaEntity source, Double valuecontainsOnly(Collection<ClientQuotaFilterComponent> components);
    }

    /**
     * InformationConstructs about the value forand returns a quota type.
filter that matches all configured *entities.
     */
 NOTE: We maintain apublic `Value`static class because additional information may be added, e.g.,ClientQuotaFilter all();

    /**
     * @return the     a list of overridden entries.filter's components
     */
    public class Value {
   Collection<ClientQuotaFilterComponent> components();

     /**
     * @return whether the *filter @paramis entry the quota entry
   strict, i.e. only includes specified components
      */
    public boolean   public Value(Entry entrystrict();
    }

    /**
 * Describes a configuration *alteration Mapsto a collection of entitiesbe made to theira resolvedclient quota valuesentity.
     */
public class ClientQuotaAlteration {

  * @param configpublic thestatic quotaclass configurationOp for{

 the requested entities
     /**/
    public ResolveClientQuotasResult(Map<QuotaEntity, KafkaFuture<Map<String, Value>>> config);

 * @param key /**
the quota type to alter
 * Returns a map from quota entity to a* future@param whichvalue canif be used to checkset then the statusexisting ofvalue theis operation.updated,
     */
    * public Map<QuotaEntity, KafkaFuture<Map<String, Value>>> config();

    /**
     *otherwise Returnsif anull, futurethe whichexisting succeedsvalue onlyis ifcleared
 all quota descriptions succeed.
     */
      public KafkaFuture<Void> all();
}

public interface Admin extends AutoCloseable {Op(String key, Double value);

    ...

    /**
     * Describes the resolved quotas* for@return the provided entities.quota type to alter
     *
     */
 @param entities the entities to describe the resolvedpublic quotas forString key();

     *  @param options/**
 the options to use
     * @return theif resolvedset quotas forthen the entities
existing value    */is updated,
    ResolveClientQuotasResult resolveClientQuotas(Collection<QuotaEntity> entities, ResolveClientQuotasOptions options);
}

AlterClientQuotas

Code Block
languagejava
titleAlterQuotas
public class AlterClientQuotasEntry {
 *      public class Op {
otherwise if null, the existing value is  /**cleared
         */
  @param   key the quota typepublic to alterDouble value();
    }

    private *final @param value if set then the existing value is updated,ClientQuotaEntity entity;
    private final Collection<Op> ops;

    /**
     * @param entity the entity whose config will be modified
     otherwise* if@param null,ops the existingalteration valueto is clearedperform
         */
        public OpClientQuotaAlteration(StringClientQuotaEntity keyentity, DoubleCollection<Op> valueops);

    }

    /**
/**
     * @param@return entity the entity whose config will be modified
     */
 @param ops the alterationpublic to perform - if value is set, then the existing value is updated,ClientQuotaEntity entity();

    /**
     *            otherwise if null, the existing value is cleared@return the alteration to perform
     */
    public AlterClientQuotasEntry(QuotaEntity entity, Collection<Op> ops();
}

DescribeClientQuotas (2.6.0)

Code Block
languagejava

public class AlterClientQuotasOptionsDescribeClientQuotasOptions extends AbstractOptions<AlterClientQuotasOptions>AbstractOptions<DescribeClientQuotasOptions> {
    //**
     * Sets whether the request should be validated without altering the configs.
     */
    public AlterClientQuotasOptions validateOnly(boolean validateOnly);
 Empty.
}

/**
 * The result of the {@link Admin#AlterClientQuotasAdmin#describeClientQuotas(Collection<AlterClientQuotasEntry>Collection, AlterClientQuotasOptionsDescribeClientQuotasOptions)} call.
 */
 * The API of this class is evolving, see {@link Admin} for details.
 */
public class AlterClientQuotasResult {
    public AlterClientQuotasResult(Map<QuotaEntity, KafkaFuture<Void>> futures);

    /**
     * Returns a map from quota entity to a future which can be used to check the status of the operationpublic class DescribeClientQuotasResult {

    /**
     * Maps an entity to its configured quota value(s). Note if no value is defined for a quota
     * type for that entity's config, then it is not included in the resulting value map.
     */
    public Map<QuotaEntity,* KafkaFuture<Void>> values();

    /**
     * Returns a future which succeeds only if all quota alterations succeed@param entities future for the collection of entities that matched the filter
     */
    public DescribeClientQuotasResult(KafkaFuture<Map<ClientQuotaEntity, Map<String, Double>>> entities);

    /**
     * Returns a map from quota entity to a future which can be used to check the status of the operation.
     */
    public KafkaFuture<Void> all KafkaFuture<Map<ClientQuotaEntity, Map<String, Double>>> entities();
}

public interface Admin extends AutoCloseable {
    ...

    /**
     * AltersDescribes theall quotasentities asmatching specifiedthe forprovided the entriesfilter that have at least one client quota configuration
     * value defined.
     * <p>
     * @param alterations the alterations to perform
     * @return the result of the alterationsThe following exceptions can be anticipated when calling {@code get()} on the future from the
     * returned {@link DescribeClientQuotasResult}:
     */ <ul>
     AlterClientQuotasResult* alterClientQuotas(Collection<AlterClientQuotasEntry> entries, AlterClientQuotasOptions options);
}

kafka-client-quotas.sh/ClientQuotasCommand:

A ClientQuotasCommand would be constructed with an associated bin/kafka-client-quotas.sh script for managing quotas via command line, and would have three modes of operation, roughly correlating to each of the API calls:

  1. Describe: Describes the quota entities for the given entity specification and their corresponding quota values, as explicitly specified in the configuration. The user may provide explicit entity types+names, or a pattern to apply to an entity type find matching entity names. If an entity type is omitted from the input, it is treated as a wildcard.
  2. Resolve: Resolves the effective quotas for an entity, including contextual information about how those quotas were derived. This includes what configuration entries matched to the entity.
  3. Alter: Modifies a quota configuration entry in an incremental manner, i.e. specify which entries to add, update, and/or remove.
Flags

Various flags will be used to accomplish these operations.

Common flags:
--bootstrap-server: The standard bootstrap server.
--command-config: Property file for the Admin client.

Operations (mutually exclusive):
--describe: Describes the entities that match the given specification, and prints out their configuration values.
--resolve: Resolves the effective quota values for an entity.
--alter: Alters the configuration for the given specification.

Entity specification flags (common to all):
--names: Comma-separated list of type=name pairs, e.g. "user=some-user,client-id=some-client-id"
--defaults: Comma-separated list of entity types with the default name, e.g. "defaults=user,client-id" (Note a separate flag is necessary since names are opaque.)

Exclusive to --describe: None.

Exclusive to --resolve: None.

Exclusive to --alter:
--add: Comma-separated list of entries to add or update to the configuration, in format "name=value".
--delete: Comma-separated list of entries to remove from the configuration, in format "name".
--validate-only: If set, validates the alteration but doesn't perform it.

Input

When specifying configuration entries, the form: quota-name[=quota-value] is used.

Output

In general, the output of the entities will be of the form: {entity-type=entity-name, ...}, where entity-name is sanitized for output since it is an opaque string. When displaying configuration values, the form: quota-name=quota-value.

Describe:

Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --describe \
                              --names=client-id=my-client

{user=user-one, client-id=my-client}
consumer_byte_rate=4000000
producer_byte_rate=1000000

{user=user-two, client-id=my-client}
producer_byte_rate=2000000

{user=<default>, client-id=my-client}
consumer_byte_rate=1000000
producer_byte_rate=500000

Resolve:

Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --resolve \
                              --names=user=user-two,client-id=my-client

consumer_byte_rate=2000000 {user=user-two, client-id=my-client}
producer_byte_rate=500000 {user=<default>, client-id=my-client}

Alter:

<li>{@link org.apache.kafka.common.errors.ClusterAuthorizationException}
     *   If the authenticated user didn't have describe access to the cluster.</li>
     *   <li>{@link org.apache.kafka.common.errors.InvalidRequestException}
     *   If the request details are invalid. e.g., an invalid entity type was specified.</li>
     *   <li>{@link org.apache.kafka.common.errors.TimeoutException}
     *   If the request timed out before the describe could finish.</li>
     * </ul>
     * <p>
     * This operation is supported by brokers with version 2.6.0 or higher.
     *
     * @param filter the filter to apply to match entities
     * @param options the options to use
     * @return the DescribeClientQuotasResult containing the result
     */
    DescribeClientQuotasResult describeClientQuotas(ClientQuotaFilter filter, DescribeClientQuotasOptions options);
}

ResolveClientQuotas (pending future release)

Code Block
languagejava
public class ResolveClientQuotasOptions extends AbstractOptions<ResolveClientQuotasOptions> {
    // Empty.
}

/**
 * The result of the {@link Admin#resolveClientQuotas(Collection, ResolveClientQuotasOptions)} call.
 */
public class ResolveClientQuotasResult {
    /**
     * Information about a specific quota configuration entry.
     */
    public class Entry {
        /**
         * @param source the entity source for the value
         * @param value the non-null value
         */
        public Entry(QuotaEntity source, Double value);
    }

    /**
     * Information about the value for a quota type.
     *
     * NOTE: We maintain a `Value` class because additional information may be added, e.g.,
     *       a list of overridden entries.
     */
    public class Value {
        /**
         * @param entry the quota entry
         */
        public Value(Entry entry);
    }

    /**
     * Maps a collection of entities to their resolved quota values.
     *
     * @param config the quota configuration for the requested entities
     */
    public ResolveClientQuotasResult(Map<QuotaEntity, KafkaFuture<Map<String, Value>>> config);

    /**
     * Returns a map from quota entity to a future which can be used to check the status of the operation.
     */
    public Map<QuotaEntity, KafkaFuture<Map<String, Value>>> config();

    /**
     * Returns a future which succeeds only if all quota descriptions succeed.
     */
    public KafkaFuture<Void> all();
}

public interface Admin extends AutoCloseable {
    ...

    /**
     * Resolves the effective quota values for the provided entities.
     *
     * @param entities the entities to describe the resolved quotas for
     * @param options the options to use
     * @return the resolved quotas for the entities
     */
    ResolveClientQuotasResult resolveClientQuotas(Collection<QuotaEntity> entities, ResolveClientQuotasOptions options);
}

AlterClientQuotas (2.6.0)

Code Block
languagejava
titleAlterQuotas
/**
 * Options for {@link Admin#alterClientQuotas(Collection, AlterClientQuotasOptions)}.
 *
 * The API of this class is evolving, see {@link Admin} for details.
 */
public class AlterClientQuotasOptions extends AbstractOptions<AlterClientQuotasOptions> {

    /**
     * Returns whether the request should be validated without altering the configs.
     */
    public boolean validateOnly();

    /**
     * Sets whether the request should be validated without altering the configs.
     */
    public AlterClientQuotasOptions validateOnly(boolean validateOnly);
}

/**
 * The result of the {@link Admin#alterClientQuotas(Collection, AlterClientQuotasOptions)} call.
 *
 * The API of this class is evolving, see {@link Admin} for details.
 */
@InterfaceStability.Evolving
public class AlterClientQuotasResult {

    /**
     * Maps an entity to its alteration result.
     *
     * @param futures maps entity to its alteration result
     */
    public AlterClientQuotasResult(Map<ClientQuotaEntity, KafkaFuture<Void>> futures);

    /**
     * Returns a map from quota entity to a future which can be used to check the status of the operation.
     */
    public Map<ClientQuotaEntity, KafkaFuture<Void>> values();

    /**
     * Returns a future which succeeds only if all quota alterations succeed.
     */
    public KafkaFuture<Void> all();
}

public interface Admin extends AutoCloseable {
    ...

    /**
     * Alters client quota configurations with the specified alterations.
     * <p>
     * Alterations for a single entity are atomic, but across entities is not guaranteed. The resulting
     * per-entity error code should be evaluated to resolve the success or failure of all updates.
     * <p>
     * The following exceptions can be anticipated when calling {@code get()} on the futures obtained from
     * the returned {@link AlterClientQuotasResult}:
     * <ul>
     *   <li>{@link org.apache.kafka.common.errors.ClusterAuthorizationException}
     *   If the authenticated user didn't have alter access to the cluster.</li>
     *   <li>{@link org.apache.kafka.common.errors.InvalidRequestException}
     *   If the request details are invalid. e.g., a configuration key was specified more than once for an entity.</li>
     *   <li>{@link org.apache.kafka.common.errors.TimeoutException}
     *   If the request timed out before the alterations could finish. It cannot be guaranteed whether the update
     *   succeed or not.</li>
     * </ul>
     * <p>
     * This operation is supported by brokers with version 2.6.0 or higher.
     *
     * @param entries the alterations to perform
     * @return the AlterClientQuotasResult containing the result
     */
    AlterClientQuotasResult alterClientQuotas(Collection<ClientQuotaAlteration> entries, AlterClientQuotasOptions options);
}

kafka-configs.sh/ConfigCommand (2.6.0)

As a result of introducing the APIs, the ConfigCommand will be updated to support the users and clients entity types when using the --bootstrap-server option.  The modification to ConfigCommand was adopted in KIP-543, and usage will remain unchanged from the original --zookeeper functionality.

kafka-client-quotas.sh/ClientQuotasCommand (pending future release)

A ClientQuotasCommand would be constructed with an associated bin/kafka-client-quotas.sh script for managing quotas via command line, and would have three modes of operation, roughly correlating to each of the API calls:

  1. Describe: Describes the quota entities for the given entity specification and their corresponding quota values, as explicitly specified in the configuration. The user may provide explicit entity types+names, or a pattern to apply to an entity type find matching entity names. If an entity type is omitted from the input, it is treated as a wildcard.
  2. Resolve: Resolves the effective quotas for an entity, including contextual information about how those quotas were derived. This includes what configuration entries matched to the entity.
  3. Alter: Modifies a quota configuration entry in an incremental manner, i.e. specify which entries to add, update, and/or remove.
Flags

Various flags will be used to accomplish these operations.

Common flags:
--bootstrap-server: The standard bootstrap server.
--command-config: Property file for the Admin client.

Operations (mutually exclusive):
--describe: Describes the entities that match the given specification, and prints out their configuration values.
--resolve: Resolves the effective quota values for an entity.
--alter: Alters the configuration for the given specification.

Entity specification flags (common to all):
--names: Comma-separated list of type=name pairs, e.g. "user=some-user,client-id=some-client-id"
--defaults: Comma-separated list of entity types with the default name, e.g. "defaults=user,client-id" (Note a separate flag is necessary since names are opaque.)

Exclusive to --describe: None.

Exclusive to --resolve: None.

Exclusive to --alter:
--add: Comma-separated list of entries to add or update to the configuration, in format "name=value".
--delete: Comma-separated list of entries to remove from the configuration, in format "name".
--validate-only: If set, validates the alteration but doesn't perform it.

Input

When specifying configuration entries, the form: quota-name[=quota-value] is used.

Output

In general, the output of the entities will be of the form: {entity-type=entity-name, ...}, where entity-name is sanitized for output since it is an opaque string. When displaying configuration values, the form: quota-name=quota-value.

Describe:

Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --describe \
                              --names=client-id=my-client

{user=user-one, client-id=my-client}
consumer_byte_rate=4000000
producer_byte_rate=1000000

{user=user-two, client-id=my-client}
producer_byte_rate=2000000

{user=<default>, client-id=my-client}
consumer_byte_rate=1000000
producer_byte_rate=500000

Resolve:

Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --resolve \
                              --names=user=user-two,client-id=my-client

consumer_byte_rate=2000000 {user=user-two, client-id=my-client}
producer_byte_rate=500000 {user=<default>, client-id=my-client}

Alter:

Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --alter   \
                              --names=client-id=my-client --defaults=user \
                              --add=consumer_byte_rate=2000000            \
                              --delete=producer_byte_rate

<no output on success>

$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --describe \
                              --names=client-id=my-client --defaults=user

{user=<default>, client-id=my-client}
consumer_byte_rate=2000000

Proposed Changes

In addition to the API changes above, the following write protocol would be implemented:

DescribeClientQuotas (2.6.0)

Code Block
{
  "apiKey": 48,
  "type": "request",
  "name": "DescribeClientQuotasRequest",
  "validVersions": "0",
  "flexibleVersions": "none",
  "fields": [
    { "name": "Components", "type": "[]ComponentData", "versions": "0+",
      "about": "Filter components to apply to quota entities.", "fields": [
      { "name": "EntityType", "type": "string", "versions": "0+",
        "about": "The entity type that the filter component applies to." },
      { "name": "MatchType", "type": "int8", "versions": "0+",
        "about": "How to match the entity {0 = exact name, 1 = default name, 2 = any specified name}." },
      { "name": "Match", "type": "string", "versions": "0+", "nullableVersions": "0+",
        "about": "The string to match against, or null if unused for the match type." }
    ]},
    { "name": "Strict", "type": "bool", "versions": "0+",
      "about": "Whether the match is strict, i.e. should exclude entities with unspecified entity types." }
  ]
}

{
  "apiKey": 48,
  "type": "response",
  "name": "DescribeClientQuotasResponse",
  "validVersions": "0",
  "flexibleVersions": "none",
  "fields": [
    { "name": "ThrottleTimeMs", "type": "int32", "versions": "0+",
      "about": "The duration in milliseconds for which the request was throttled due to a quota violation, or zero if the request did not violate any quota." },
    { "name": "ErrorCode", "type": "int16", "versions": "0+",
      "about": "The error code, or `0` if the quota description succeeded." },
    { "name": "ErrorMessage", "type": "string", "versions": "0+", "nullableVersions": "0+",
      "about": "The error message, or `null` if the quota description succeeded." },
    { "name": "Entries", "type": "[]EntryData", "versions": "0+", "nullableVersions": "0+",
      "about": "A result entry.", "fields": [
      { "name": "Entity", "type": "[]EntityData", "versions": "0+",
        "about": "The quota entity description.", "fields": [
        { "name": "EntityType", "type": "string", "versions": "0+",
Code Block
$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --alter   \
          "about": "The entity type." },
        { "name": "EntityName", "type": "string", "versions": "0+",  --names=client-id=my-client --defaults=user \
"nullableVersions": "0+",
          "about": "The entity name, or null if the default." }
      ]},
       --add=consumer_byte_rate=2000000            \{ "name": "Values", "type": "[]ValueData", "versions": "0+",
	"about": "The quota values for the entity.", "fields": [
        { "name": "Key", "type": "string", "versions": "0+",
          "about": "The quota configuration   --delete=producer_byte_rate

<no output on success>

$./bin/kafka-client-quotas.sh --bootstrap-server localhost:9092 --describe \
       key." },
        { "name": "Value", "type": "float64", "versions": "0+",
          "about": "The quota configuration value." }
      ]}
   --names=client-id=my-client --defaults=user

{user=<default>, client-id=my-client}
consumer_byte_rate=2000000

...

 ]}
  ]
}

ResolveClientQuotas (pending future release)

In addition to the API changes above, the following write protocol would be implemented:

DescribeClientQuotas:

Code Block
{
  "apiKey": 4850,
  "type": "request",
  "name": "DescribeClientQuotasRequestResolveClientQuotasRequest",
  "validVersions": "0",
  "flexibleVersions": "none",
  "fields": [
    { "name": "FilterEntity", "type": "[]QuotaFilterDataQuotaEntityData", "versions": "0+",
      "about": "FiltersThe toquota apply to quota entitiesentity description.", "fields": [
      { "name": "EntityType", "type": "string", "versions": "0+",
        "about": "The entity type that the filter applies to." },
      { "name": "MatchEntityName", "type": "string", "versions": "0+",
        "about": "The string to match againstentity name." }
    ]}
  ]
}

{
  "apiKey": 4850,
  "type": "response",
  "name": "DescribeClientQuotasResponseResolveClientQuotasResponse",
  "validVersions": "0",
  "flexibleVersions": "none",
  "fields": [
    { "name": "ThrottleTimeMs", "type": "int32", "versions": "0+",
      "about": "The duration in milliseconds for which the request was throttled due to a quota violation, or zero if the request did not violate any quota." },
    { "name": "Entry", "type": "[]EntryDataQuotaEntryData", "versions": "0+",
      "about": "AResolved resultquota entryentries.", "fields": [
      { "name": "ErrorCode", "type": "int16", "versions": "0+",
        "about": "The error code, or `0` if the resolved quota description succeeded." },
      { "name": "ErrorMessage", "type": "string", "versions": "0+", "nullableVersions": "0+",
        "about": "The error message, or `null` if the resolved quota description succeeded." },
      { "name": "EntityQuotaEntity", "type": "[]QuotaEntityDataQuotaEntity", "versions": "0+",
        "about": "TheResolved quota entity descriptionentries.", "fields": [
        { "name": "EntityType", "type": "string", "versions": "0+",
          "about": "The entity type." },
        { "name": "EntityName", "type": "string", "versions": "0+",
          "about": "The entity name." }
      ]},
      { "name": "TypeQuotaValues", "type": "string[]QuotaValueData", "versions": "0+",
        "about": "TheQuota quotaconfiguration typevalues." },
, "fields": [
        { "name": "DoubleValueType", "type": "int64string", "versions": "0+",
          "about": "The quota value, in serialized format." }
 type." },
        { "name": "Entry", "type": "[]ValueEntryData", "versions": "0+",
       ]}
   ]
}

ResolveClientQuotas:

Code Block
{
  "apiKey": 49,
  "type"about": "Quota value entries.", "fields": [
          { "name": "requestQuotaEntity",
  "nametype": "ResolveClientQuotasRequest[]ValueQuotaEntity",
  "validVersionsversions": "0+",
            "flexibleVersionsabout": "noneResolved quota entries.",
  "fields": [
            { "name": "EntityEntityType", "type": "[]QuotaEntityDatastring", "versions": "0+",
              "about": "The quota entity descriptiontype." }, "fields": [

            { "name": "EntityTypeEntityName", "type": "string", "versions": "0+",
",
              "about": "The entity typename." }
          ]},
          { "name": "EntityNameValue", "type": "stringdouble", "versions": "0+",
            "about": "The entityquota configuration namevalue." }
        ]}
      ]},
    ]}
  ]
}

AlterClientQuotas (2.6.0)

Code Block
{
  "apiKey": 49,

{  "type": "request",
  "name": "AlterClientQuotasRequest",
  "apiKeyvalidVersions": 49"0",
  "typeflexibleVersions": "responsenone",
  "fields": [
    { "name": "ResolveClientQuotasResponseEntries",
  "type": "[]EntryData", "validVersionsversions": "0+",
      "flexibleVersionsabout": "noneThe quota configuration entries to alter.",
  "fields": [
      { "name": "ThrottleTimeMsEntity", "type": "int32[]EntityData", "versions": "0+",
        "about": "The duration in milliseconds for which the request was throttled due to a quota violation, or zero if the request did not violate any quota quota entity to alter.", "fields": [
        { "name": "EntityType", "type": "string", "versions": "0+",
          "about": "The entity type." },
        { "name": "EntryEntityName", "type": "[]QuotaEntryDatastring", "versions": "0+", "nullableVersions": "0+",
          "about": "Resolved quota entries.", "fields": [The name of the entity, or null if the default." }
      ]},
      { "name": "ErrorCodeOps", "type": "int16[]OpData", "versions": "0+",
        "about": "TheAn errorindividual code,quota orconfiguration `0`entry if the resolved quota description succeeded." },
to alter.", "fields": [
        { "name": "ErrorMessageKey", "type": "string", "versions": "0+",
 "nullableVersions": "0+",
        "about": "The error message, or `null` if the resolved quota descriptionconfiguration succeededkey." },
        { "name": "QuotaEntityValue", "type": "[]QuotaEntityfloat64", "versions": "0+",
        "about": "Resolved quota entries.", "fields": [
          "about": "The value to set, otherwise ignored if the value is to be removed." },
        { "name": "EntityTypeRemove", "type": "stringbool", "versions": "0+",
          "about": "The entity typeWhether the quota configuration value should be removed, otherwise set." },
      ]}
    ]},
    { "name": "EntityNameValidateOnly", "type": "stringbool", "versions": "0+",
          "about": "The entity nameWhether the alteration should be validated, but not performed." }
   ]
}

{
   ]}"apiKey": 49,
      { "nametype": "QuotaValuesresponse",
  "typename": "[]QuotaValueDataAlterClientQuotasResponse",
  "versionsvalidVersions": "0+",
        "about"flexibleVersions": "Quota configuration values.none",
  "fields": [
        { "name": "TypeThrottleTimeMs", "type": "stringint32", "versions": "0+",
      "about": "The duration in milliseconds for which the request was throttled due to a quota violation, or zero if the request did not "about": "Theviolate any quota type." },
        { "name": "EntryEntries", "type": "[]ValueEntryDataEntryData", "versions": "0+",
          "about": "QuotaThe quota valueconfiguration entries to alter.", "fields": [
          { "name": "QuotaEntityErrorCode", "type": "[]ValueQuotaEntityint16", "versions": "0+",
            "about": "ResolvedThe quotaerror entries."code, "fields": [
      or `0` if the quota alteration succeeded." },
      { "name": "EntityTypeErrorMessage", "type": "string", "versions": "0+",
 "nullableVersions": "0+",
            "about": "The entity type error message, or `null` if the quota alteration succeeded." },
            { "name": "EntityNameEntity", "type": "string[]EntityData", "versions": "0+",
              "about": "The quota entity nameto alter." }
          ]},, "fields": [
          { "name": "DooubleValueEntityType", "type": "int64string", "versions": "0+",
            "about": "The quota configuration value, in serialized formatentity type." }
        ]}
  ,
    ]}
    ]}
  ]
}

AlterClientQuotas:

Code Block
{
  "apiKeyname": 50"EntityName",
  "type": "requeststring",
  "nameversions": "AlterClientQuotasRequest0+",
  "validVersionsnullableVersions": "0+",
   "flexibleVersions       "about": "none",
  "fields": [
    { "name": "Entry", "type": "[]EntryData", "versions": "0+",The name of the entity, or null if the default." }
      ]}
    ]}
  ]
}

Kafka RPC 'double' support (2.6.0)

Note that, while the ByteBuffer natively supports serializing a Double, the format in which the value is serialized is not strongly specified, so the preference is to explicitly ensure a standard representation of double-precision 64-bit IEEE 754 format. This is achieved in Java using Double.doubleToRawLongBits() and Double.longBitsToDouble() and should be easily portable to other languages.

Code Block
titleclients/src/main/java/org/apache/kafka/common/utils/ByteUtils.java
    /**
      "about": "The quota configuration entries to alter.", "fields": [* Read a double-precision 64-bit format IEEE 754 value.
     *
 { "name": "QuotaEntity", "type": "[]QuotaEntity", "versions": "0+",
        "about": "The quota entity to alter.", "fields": [ * @param buffer The buffer to read from
     * @return The long value read
     */
   { "name": "EntityType", "type": "string", "versions": "0+",public static double readDouble(ByteBuffer buffer) {
        return  "about": "The entity type." },
 Double.longBitsToDouble(buffer.getLong());
    }

    /**
     * Write { "name": "EntityName", "type": "string", "versions": "0+",
          "about": "The name of the entity." }
      ]},the given double following the double-precision 64-bit format IEEE 754 value into the buffer.
     *
     * @param value The value to write
     * { "name": "Op", "type": "[]OpData", "versions": "0+",@param buffer The buffer to write to
      */
  "about": "An individualpublic quotastatic configurationvoid entry to alter.", "fields": [writeDouble(double value, ByteBuffer buffer) {
        { buffer.putLong(Double.doubleToRawLongBits(value));
    }

The protocol type definition:

Code Block
titleclients/src/main/java/org/apache/kafka/common/protocol/types/Type.java
    public static final DocumentedType DOUBLE = new DocumentedType() {
        @Override
 "name": "Type", "type": "string", "versions": "0+",
          "about": "The quota type." },
       public { "name": "DoubleValue", "type": "int64", "versions": "0+",
void write(ByteBuffer buffer, Object o) {
           "about": "The value to set, in serialized format, otherwise ignored if the value is to be removed." },
   ByteUtils.writeDouble((Double) o, buffer);
        }

        @Override
      { "name": "Remove", "type": "bool", "versions": "0+", public Object read(ByteBuffer buffer) {
          "about": "Whether the quota configuration value should be removed, otherwise set." }return ByteUtils.readDouble(buffer);
        }

      ]}  @Override
    ]},
    { "name": "ValidateOnly", "type": "bool", "versions": "0+",
public int sizeOf(Object o) {
         "about": "Whether the alterationreturn should8;
 be validated, but not performed." }
  ]
}

{
    "apiKey": 50,
  "type": "response",
  "name": "AlterClientQuotasResponse",
  "validVersions": "0",
  "flexibleVersions": "none",
  "fields": [
 @Override
        public String typeName() {
       { "name": "ThrottleTimeMs", "type": "int32", "versions": return "0+DOUBLE",;
        }

    "about": "The duration in milliseconds@Override
 for which the request was throttled due topublic aDouble quota violation, or zero if the request did not violate any quota." },
    { "name": "Entry", "type": "[]EntryData", "versions": "0+",
validate(Object item) {
            if (item instanceof Double)
          "about": "The quota configuration entries to alter.", "fields": [return (Double) item;
      { "name": "ErrorCode", "type": "int16", "versions": "0+", else
        "about": "The error code, or `0` if the quotathrow alteration succeeded." },
      { "name": "ErrorMessage", "type": "string", "versions": "0+", "nullableVersions": "0+",new SchemaException(item + " is not a Double.");
        }

        "about": "The error message, or `null` if the quota alteration succeeded." },
@Override
        public String documentation() {
       { "name": "QuotaEntity", "type": "[]QuotaEntity", "versions": "0+",
        "about": "The quota entity to alter.", "fields": [
 return "Represents a double-precision 64-bit format IEEE 754 value. " +
              { "name": "EntityType", "type": "string", "versions": "0+",
          "about": "The entity type." },
        { "name": "EntityName", "type": "string", "versions": "0+",
          "about": "The name of the entity." }
      ]}
    ]}
  ]
}    "The values are encoded using eight bytes in network byte order (big-endian).";
        }
    };


In generator/src/main/java/org/apache/kafka/message/MessageGenerator.java, the following operations will be used (code omitted for brevity):

Code Block
titlegenerator/src/main/java/org/apache/kafka/message/MessageGenerator.java
Hash code: Double.hashCode(value)

Empty value: (double) 0

Parsing a default value string: Double.parseDouble(defaultValue)

Compatibility, Deprecation, and Migration Plan

All changes would be are forward-compatible, and no migration plan is necessary. It's outside the scope of this KIP to deprecate any functionality.

Rejected Alternatives

  • Use existing describeConfigs/incrementalAlterConfigs for quota functionality. This falls short for a couple reasons. First, quotas entity names are more dynamic than brokers and tasks which makes them awkward to fit into generic tools which expect a single unique, distinct key, e.g. ConfigCommand. Second, there's no tool that expresses a way to get the resolved quota for an entity without some heavy engineering on the client side, which lacks extensibility and is more expensive to perform, especially over large collection of entities. Therefore, it makes sense to approach quotas as a standalone set of APIs that provide more targeted information and can properly support future extensibility.

...