%%% %%% Copyright (c) 2014-2017, Klarna AB %%% %%% Licensed under the Apache License, Version 2.0 (the "License"); %%% you may not use this file except in compliance with the License. %%% You may obtain a copy of the License at %%% %%% http://www.apache.org/licenses/LICENSE-2.0 %%% %%% Unless required by applicable law or agreed to in writing, software %%% distributed under the License is distributed on an "AS IS" BASIS, %%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %%% See the License for the specific language governing permissions and %%% limitations under the License. %%% -module(brod). -behaviour(application). %% Application -export([ start/0 , start/2 , stop/0 , stop/1 ]). %% Client API -export([ get_partitions_count/2 , start_client/1 , start_client/2 , start_client/3 , start_consumer/3 , start_producer/3 , stop_client/1 ]). %% Client API (deprecated) -export([ start_link_client/1 , start_link_client/2 , start_link_client/3 ]). %% Producer API -export([ get_producer/3 , produce/2 , produce/3 , produce/5 , produce_sync/2 , produce_sync/3 , produce_sync/5 , sync_produce_request/1 , sync_produce_request/2 ]). %% Simple Consumer API -export([ consume_ack/2 , consume_ack/4 , get_consumer/3 , subscribe/3 , subscribe/5 , unsubscribe/1 , unsubscribe/2 , unsubscribe/3 , unsubscribe/4 ]). %% Subscriber API -export([ start_link_group_subscriber/7 , start_link_topic_subscriber/5 , start_link_topic_subscriber/6 ]). %% APIs for quick metadata or message inspection and brod_cli -export([ get_metadata/1 , get_metadata/2 , get_metadata/3 , get_offsets/3 , get_offsets/5 , get_offsets/6 , fetch/4 , fetch/7 , fetch/8 , connect_leader/4 ]). %% escript -ifdef(BROD_CLI). -export([main/1]). -endif. -deprecated([{start_link_client, '_', next_version}]). -export_type([ brod_call_ref/0 , brod_client_id/0 , brod_partition_fun/0 , client/0 , client_config/0 , consumer_config/0 , consumer_options/0 , endpoint/0 , group_config/0 , group_id/0 , key/0 , kpro_MetadataResponse/0 , kv_list/0 , offset/0 , offset_time/0 , producer_config/0 , topic/0 , value/0 ]). -include("brod_int.hrl"). %%%_* APIs ===================================================================== %% @doc Start brod application. -spec start() -> ok | no_return(). start() -> {ok, _Apps} = application:ensure_all_started(brod), ok. %% @doc Stop brod application. -spec stop() -> ok. stop() -> application:stop(brod). %% @doc Application behaviour callback start(_StartType, _StartArgs) -> brod_sup:start_link(). %% @doc Application behaviour callback stop(_State) -> ok. %% @equiv stat_client(BootstrapEndpoints, brod_default_client) -spec start_client([endpoint()]) -> ok | {error, any()}. start_client(BootstrapEndpoints) -> start_client(BootstrapEndpoints, ?BROD_DEFAULT_CLIENT_ID). %% @equiv stat_client(BootstrapEndpoints, ClientId, []) -spec start_client([endpoint()], brod_client_id()) -> ok | {error, any()}. start_client(BootstrapEndpoints, ClientId) -> start_client(BootstrapEndpoints, ClientId, []). %% @doc Start a client. %% BootstrapEndpoints: %% Kafka cluster endpoints, can be any of the brokers in the cluster %% which does not necessarily have to be a leader of any partition, %% e.g. a load-balanced entrypoint to the remote kakfa cluster. %% ClientId: %% Atom to identify the client process %% Config: %% Proplist, possible values: %% restart_delay_seconds (optional, default=10) %% How much time to wait between attempts to restart brod_client %% process when it crashes %% max_metadata_sock_retry (optional, default=1) %% Number of retries if failed fetching metadata due to socket error %% get_metadata_timeout_seconds(optional, default=5) %% Return timeout error from brod_client:get_metadata/2 in case the %% respons is not received from kafka in this configured time. %% reconnect_cool_down_seconds (optional, default=1) %% Delay this configured number of seconds before retrying to %% estabilish a new connection to the kafka partition leader. %% allow_topic_auto_creation (optional, default=true) %% By default, brod respects what is configured in broker about %% topic auto-creation. i.e. whatever auto.create.topics.enable %% is set in borker configuration. %% However if 'allow_topic_auto_creation' is set to 'false' in client %% config, brod will avoid sending metadata requests that may cause an %% auto-creation of the topic regardless of what the broker config is. %% auto_start_producers (optional, default=false) %% If true, brod client will spawn a producer automatically when %% user is trying to call 'produce' but did not call %% brod:start_producer explicitly. Can be useful for applications %% which don't know beforehand which topics they will be working with. %% default_producer_config (optional, default=[]) %% Producer configuration to use when auto_start_producers is true. %% @see brod_producer:start_link/4. for details about producer config %% ssl (optional, default=false) %% true | false | [{certfile, ...},{keyfile, ...},{cacertfile, ...}] %% When true, brod will try to upgrade tcp connection to ssl using default %% ssl options. List of ssl options implies ssl=true. %% sasl (optional, default=undefined) %% Credentials for SASL/Plain authentication. %% {plain, "username", "password"} %% connect_timeout (optional, default=5000) %% Timeout when trying to connect to one endpoint. %% request_timeout (optional, default=240000, constraint: >= 1000) %% Timeout when waiting for a response, socket restart when timedout. %% @end -spec start_client([endpoint()], brod_client_id(), client_config()) -> ok | {error, any()}. start_client(BootstrapEndpoints, ClientId, Config) -> case brod_sup:start_client(BootstrapEndpoints, ClientId, Config) of ok -> ok; {error, {already_started, _Pid}} -> ok; {error, Reason} -> {error, Reason} end. %% @equiv stat_link_client(BootstrapEndpoints, brod_default_client) -spec start_link_client([endpoint()]) -> {ok, pid()} | {error, any()}. start_link_client(BootstrapEndpoints) -> start_link_client(BootstrapEndpoints, ?BROD_DEFAULT_CLIENT_ID). %% @equiv stat_link_client(BootstrapEndpoints, ClientId, []) -spec start_link_client([endpoint()], brod_client_id()) -> {ok, pid()} | {error, any()}. start_link_client(BootstrapEndpoints, ClientId) -> start_link_client(BootstrapEndpoints, ClientId, []). -spec start_link_client([endpoint()], brod_client_id(), client_config()) -> {ok, pid()} | {error, any()}. start_link_client(BootstrapEndpoints, ClientId, Config) -> brod_client:start_link(BootstrapEndpoints, ClientId, Config). %% @doc Stop a client. -spec stop_client(client()) -> ok. stop_client(Client) when is_atom(Client) -> case brod_sup:find_client(Client) of [_Pid] -> brod_sup:stop_client(Client); [] -> brod_client:stop(Client) end; stop_client(Client) when is_pid(Client) -> brod_client:stop(Client). %% @doc Dynamically start a per-topic producer. %% @see brod_producer:start_link/4. for details about producer config. %% @end -spec start_producer(client(), topic(), producer_config()) -> ok | {error, any()}. start_producer(Client, TopicName, ProducerConfig) -> brod_client:start_producer(Client, TopicName, ProducerConfig). %% @doc Dynamically start a topic consumer. %% @see brod_consumer:start_link/5. for details about consumer config. %% @end -spec start_consumer(client(), topic(), consumer_config()) -> ok | {error, any()}. start_consumer(Client, TopicName, ConsumerConfig) -> brod_client:start_consumer(Client, TopicName, ConsumerConfig). %% @doc Get number of partitions for a given topic. %% The higher level producers may need the partition numbers to %% find the partition producer pid --- if the number of partitions %% is not statically configured for them. %% It is up to the callers how they want to distribute their data %% (e.g. random, roundrobin or consistent-hashing) to the partitions. %% @end -spec get_partitions_count(client(), topic()) -> {ok, pos_integer()} | {error, any()}. get_partitions_count(Client, Topic) -> brod_client:get_partitions_count(Client, Topic). -spec get_consumer(client(), topic(), partition()) -> {ok, pid()} | {error, Reason} when Reason :: client_down | {consumer_down, noproc} | {consumer_not_found, topic()} | {consumer_not_found, topic(), partition()}. get_consumer(Client, Topic, Partition) -> brod_client:get_consumer(Client, Topic, Partition). %% @equiv brod_client:get_producer/3 -spec get_producer(client(), topic(), partition()) -> {ok, pid()} | {error, Reason} when Reason :: client_down | {producer_down, noproc} | {producer_not_found, topic()} | {producer_not_found, topic(), partition()}. get_producer(Client, Topic, Partition) -> brod_client:get_producer(Client, Topic, Partition). %% @equiv produce(Pid, 0, <<>>, Value) -spec produce(pid(), value()) -> {ok, brod_call_ref()} | {error, any()}. produce(Pid, Value) -> produce(Pid, _Key = <<>>, Value). %% @doc Produce one message if Value is binary or iolist, %% or a message set if Value is a (nested) kv-list, in this case Key %% is discarded (only the keys in kv-list are sent to kafka). %% The pid should be a partition producer pid, NOT client pid. %% @end -spec produce(pid(), key(), value()) -> {ok, brod_call_ref()} | {error, any()}. produce(ProducerPid, Key, Value) -> brod_producer:produce(ProducerPid, Key, Value). %% @doc Produce one message if Value is binary or iolist, %% or a message set if Value is a (nested) kv-list, in this case Key %% is used only for partitioning (or discarded if Partition is used %% instead of PartFun). %% This function first lookup the producer pid, %% then call produce/3 to do the real work. %% @end -spec produce(client(), topic(), partition() | brod_partition_fun(), key(), value()) -> {ok, brod_call_ref()} | {error, any()}. produce(Client, Topic, PartFun, Key, Value) when is_function(PartFun) -> case brod_client:get_partitions_count(Client, Topic) of {ok, PartitionsCnt} -> {ok, Partition} = PartFun(Topic, PartitionsCnt, Key, Value), produce(Client, Topic, Partition, Key, Value); {error, Reason} -> {error, Reason} end; produce(Client, Topic, Partition, Key, Value) when is_integer(Partition) -> case get_producer(Client, Topic, Partition) of {ok, Pid} -> produce(Pid, Key, Value); {error, Reason} -> {error, Reason} end. %% @equiv produce_sync(Pid, 0, <<>>, Value) -spec produce_sync(pid(), value()) -> ok. produce_sync(Pid, Value) -> produce_sync(Pid, _Key = <<>>, Value). %% @doc Sync version of produce/3 %% This function will not return until a response is received from kafka, %% however if producer is started with required_acks set to 0, this function %% will return onece the messages is buffered in the producer process. %% @end -spec produce_sync(pid(), key(), value()) -> ok | {error, any()}. produce_sync(Pid, Key, Value) -> case produce(Pid, Key, Value) of {ok, CallRef} -> %% Wait until the request is acked by kafka sync_produce_request(CallRef); {error, Reason} -> {error, Reason} end. %% @doc Sync version of produce/5 %% This function will not return until a response is received from kafka, %% however if producer is started with required_acks set to 0, this function %% will return once the messages are buffered in the producer process. %% @end -spec produce_sync(client(), topic(), partition() | brod_partition_fun(), key(), value()) -> ok | {error, any()}. produce_sync(Client, Topic, Partition, Key, Value) -> case produce(Client, Topic, Partition, Key, Value) of {ok, CallRef} -> sync_produce_request(CallRef); {error, Reason} -> {error, Reason} end. %% @doc Block wait for sent produced request to be acked by kafka. -spec sync_produce_request(brod_call_ref()) -> ok | {error, Reason :: any()}. sync_produce_request(CallRef) -> sync_produce_request(CallRef, infinity). -spec sync_produce_request(brod_call_ref(), infinity | timer:time()) -> ok | {error, Reason :: any()}. sync_produce_request(CallRef, Timeout) -> Expect = #brod_produce_reply{ call_ref = CallRef , result = brod_produce_req_acked }, brod_producer:sync_produce_request(Expect, Timeout). %% @doc Subscribe data stream from the given topic-partition. %% If {error, Reason} is returned, the caller should perhaps retry later. %% {ok, ConsumerPid} is returned if success, the caller may want to monitor %% the consumer pid to trigger a re-subscribe in case it crashes. %% %% If subscribed successfully, the subscriber process should expect messages %% of pattern: %% {ConsumerPid, #kafka_message_set{}} and %% {ConsumerPid, #kafka_fetch_error{}}, %% -include_lib(brod/include/brod.hrl) to access the records. %% In case #kafka_fetch_error{} is received the subscriber should re-subscribe %% itself to resume the data stream. %% @end -spec subscribe(client(), pid(), topic(), partition(), consumer_options()) -> {ok, pid()} | {error, any()}. subscribe(Client, SubscriberPid, Topic, Partition, Options) -> case brod_client:get_consumer(Client, Topic, Partition) of {ok, ConsumerPid} -> case subscribe(ConsumerPid, SubscriberPid, Options) of ok -> {ok, ConsumerPid}; Error -> Error end; {error, Reason} -> {error, Reason} end. -spec subscribe(pid(), pid(), consumer_options()) -> ok | {error, any()}. subscribe(ConsumerPid, SubscriberPid, Options) -> brod_consumer:subscribe(ConsumerPid, SubscriberPid, Options). %% @doc Unsubscribe the current subscriber. Assuming the subscriber is self(). -spec unsubscribe(client(), topic(), partition()) -> ok | {error, any()}. unsubscribe(Client, Topic, Partition) -> unsubscribe(Client, Topic, Partition, self()). %% @doc Unsubscribe the current subscriber. -spec unsubscribe(client(), topic(), partition(), pid()) -> ok | {error, any()}. unsubscribe(Client, Topic, Partition, SubscriberPid) -> case brod_client:get_consumer(Client, Topic, Partition) of {ok, ConsumerPid} -> unsubscribe(ConsumerPid, SubscriberPid); Error -> Error end. %% @doc Unsubscribe the current subscriber. Assuming the subscriber is self(). -spec unsubscribe(pid()) -> ok | {error, any()}. unsubscribe(ConsumerPid) -> unsubscribe(ConsumerPid, self()). %% @doc Unsubscribe the current subscriber. -spec unsubscribe(pid(), pid()) -> ok | {error, any()}. unsubscribe(ConsumerPid, SubscriberPid) -> brod_consumer:unsubscribe(ConsumerPid, SubscriberPid). -spec consume_ack(client(), topic(), partition(), offset()) -> ok | {error, any()}. consume_ack(Client, Topic, Partition, Offset) -> case brod_client:get_consumer(Client, Topic, Partition) of {ok, ConsumerPid} -> consume_ack(ConsumerPid, Offset); {error, Reason} -> {error, Reason} end. -spec consume_ack(pid(), offset()) -> ok | {error, any()}. consume_ack(ConsumerPid, Offset) -> brod_consumer:ack(ConsumerPid, Offset). %% @equiv brod_group_subscriber:start_link/7 -spec start_link_group_subscriber( client(), group_id(), [topic()], group_config(), consumer_config(), module(), term()) -> {ok, pid()} | {error, any()}. start_link_group_subscriber(Client, GroupId, Topics, GroupConfig, ConsumerConfig, CbModule, CbInitArg) -> brod_group_subscriber:start_link(Client, GroupId, Topics, GroupConfig, ConsumerConfig, CbModule, CbInitArg). %% @equiv start_link_topic_subscriber(Client, Topic, 'all', ConsumerConfig, %% CbModule, CbInitArg) -spec start_link_topic_subscriber( client(), topic(), consumer_config(), module(), term()) -> {ok, pid()} | {error, any()}. start_link_topic_subscriber(Client, Topic, ConsumerConfig, CbModule, CbInitArg) -> start_link_topic_subscriber(Client, Topic, all, ConsumerConfig, CbModule, CbInitArg). %% @equiv brod_topic_subscriber:start_link/6 -spec start_link_topic_subscriber( client(), topic(), all | [partition()], consumer_config(), module(), term()) -> {ok, pid()} | {error, any()}. start_link_topic_subscriber(Client, Topic, Partitions, ConsumerConfig, CbModule, CbInitArg) -> brod_topic_subscriber:start_link(Client, Topic, Partitions, ConsumerConfig, CbModule, CbInitArg). %% @doc Fetch broker metadata -spec get_metadata([endpoint()]) -> {ok, kpro_MetadataResponse()} | {error, any()}. get_metadata(Hosts) -> brod_utils:get_metadata(Hosts). %% @doc Fetch broker metadata -spec get_metadata([endpoint()], [topic()]) -> {ok, kpro_MetadataResponse()} | {error, any()}. get_metadata(Hosts, Topics) -> brod_utils:get_metadata(Hosts, Topics). %% @doc Fetch broker metadata -spec get_metadata([endpoint()], [topic()], brod_sock:options()) -> {ok, kpro_MetadataResponse()} | {error, any()}. get_metadata(Hosts, Topics, Options) -> brod_utils:get_metadata(Hosts, Topics, Options). %% @equiv get_offsets(Hosts, Topic, Partition, latest, 1) -spec get_offsets([endpoint()], topic(), non_neg_integer()) -> {ok, [offset()]} | {error, any()}. get_offsets(Hosts, Topic, Partition) -> get_offsets(Hosts, Topic, Partition, ?OFFSET_LATEST, 1). %% @doc Get valid offsets for a specified topic/partition -spec get_offsets([endpoint()], topic(), partition(), offset_time(), pos_integer()) -> {ok, [offset()]} | {error, any()}. get_offsets(Hosts, Topic, Partition, TimeOrSemanticOffset, MaxNoOffsets) -> get_offsets(Hosts, Topic, Partition, TimeOrSemanticOffset, MaxNoOffsets, []). -spec get_offsets([endpoint()], topic(), partition(), offset_time(), pos_integer(), brod_sock:options()) -> {ok, [offset()]} | {error, any()}. get_offsets(Hosts, Topic, Partition, TimeOrSemanticOffset, MaxNoOffsets, Options) -> {ok, Pid} = connect_leader(Hosts, Topic, Partition, Options), try brod_utils:fetch_offsets(Pid, Topic, Partition, TimeOrSemanticOffset, MaxNoOffsets) after ok = brod_sock:stop(Pid) end. %% @equiv fetch(Hosts, Topic, Partition, Offset, 1000, 0, 100000) -spec fetch([endpoint()], topic(), partition(), integer()) -> {ok, [#kafka_message{} | ?incomplete_message]} | {error, any()}. fetch(Hosts, Topic, Partition, Offset) -> fetch(Hosts, Topic, Partition, Offset, _MaxWaitTime = 1000, _MinBytes = 0, _MaxBytes = 100000). %% @doc Fetch a single message set from the given topic-partition. -spec fetch([endpoint()], topic(), partition(), offset(), non_neg_integer(), non_neg_integer(), pos_integer()) -> {ok, [#kafka_message{}]} | {error, any()}. fetch(Hosts, Topic, Partition, Offset, MaxWaitTime, MinBytes, MaxBytes) -> fetch(Hosts, Topic, Partition, Offset, MaxWaitTime, MinBytes, MaxBytes, []). %% @doc Fetch a single message set from the given topic-partition. -spec fetch([endpoint()], topic(), partition(), offset(), non_neg_integer(), non_neg_integer(), pos_integer(), brod_sock:options()) -> {ok, [#kafka_message{}]} | {error, any()}. fetch(Hosts, Topic, Partition, Offset, MaxWaitTime, MinBytes, MaxBytes0, Options) -> {ok, Pid} = connect_leader(Hosts, Topic, Partition, Options), ReqFun = fun(MaxBytes) -> kpro:fetch_request(Topic, Partition, Offset, MaxWaitTime, MinBytes, MaxBytes) end, try brod_utils:fetch(Pid, ReqFun, MaxBytes0, Offset) after ok = brod_sock:stop(Pid) end. %% @doc Connect partition leader. -spec connect_leader([endpoint()], topic(), partition(), brod_sock:options()) -> {ok, pid()}. connect_leader(Hosts, Topic, Partition, Options) -> {ok, Metadata} = get_metadata(Hosts, [Topic], Options), {ok, {Host, Port}} = brod_utils:find_leader_in_metadata(Metadata, Topic, Partition), %% client id matters only for producer clients brod_sock:start_link(self(), Host, Port, ?BROD_DEFAULT_CLIENT_ID, Options). -ifdef(BROD_CLI). main(Args) -> brod_cli:main(Args, halt). -endif. %%%_* Emacs ==================================================================== %%% Local Variables: %%% allout-layout: t %%% erlang-indent-level: 2 %%% End: