java - Why Kafka KTable is missing entries? -


i have single instance java application uses ktable kafka streams. until retrieve data using ktable when of messages seemed vanish. there should ~33k messages unique keys there.

when want retrieve messages key don't of messages. use readonlykeyvaluestore retrieve messages:

final readonlykeyvaluestore<genericrecord, genericrecord> store = ((kafkastreams)streams).store(storename, queryablestoretypes.keyvaluestore()); store.get(key);

these configuration settings set kafkastreams.

final properties config = new properties(); config.put(streamsconfig.application_server_config, serverid); config.put(streamsconfig.application_id_config, applicationid); config.put(streamsconfig.bootstrap_servers_config, bootstrapservers); config.put(consumerconfig.auto_offset_reset_config, "earliest"); config.put(abstractkafkaavroserdeconfig.schema_registry_url_config, schemaregistryurl); config.put(streamsconfig.key_serde_class_config, genericavroserde.class); config.put(streamsconfig.value_serde_class_config, genericavroserde.class); config.put(streamsconfig.cache_max_bytes_buffering_config, 0);

kafka: 0.10.2.0-cp1
confluent: 3.2.0

investigations brought me worrying insights. using rest proxy manually read partitions , found out offsets return error.

request: /topics/{topic}/partitions/{partition}/messages?offset={offset}

{     "error_code": 50002,     "message": "kafka error: fetch response contains error code: 1" }

no client, neither java nor command line return error. skip on faulty missing messages resulting in missing data in ktables. fine , without notice seems somehow of messages got corrupt.

i have 2 brokers , topics have replication factor of 2 , replicated. both brokers separately return same. restarting brokers makes no difference.

  • what possibly cause?
  • how detect case in client?

by default kafka broker config key cleanup.policy set delete. set compact keep latest message each key. see compaction.

deletion of old messages not change minimum offset trying retrieve message below causes error. error vague. kafka streams client start reading messages minimum offset there no error. visible effect missing data in ktables.

while application running caches data might still available after messages deleted kafka itself. vanish after cleanup.


Comments

Post a Comment

Popular posts from this blog

inversion of control - Autofac named registration constructor injection -

does autofac support specifying registration name in components' constructors? example: ninject's namedattribute . you need use autofac.extras.attributed package on top achieve this so let's have 1 interface , 2 classes: public interface ihello { string sayhello(); } public class englishhello : ihello { public string sayhello() { return "hello"; } } public class frenchhello : ihello { public string sayhello() { return "bonjour"; } } then have consumer class, in want select instance injected: public class helloconsumer { private readonly ihello helloservice; public helloconsumer([withkey("en")] ihello helloservice) { if (helloservice == null) { throw new argumentnullexception("helloservice"); } this.helloservice = helloservice; } public string sayhello() { return this.helloservice.sayhello()...
Read more

verilog - Systemverilog dynamic casting issues -

i've code snippet following in testbench function void write_to_port( my_data_type_base data ); my_data_type_extended data_ext; if(!$cast(data_ext, data)); `uvm_error(get_type_name(), "failed cast"); `uvm_info(get_name(), $psprintf("data_ext :\n%s", data_ext.sprint()), uvm_medium) // write data_ext out port.... endfunction when run it, i'm getting uvm_error "failed cast." i'm not quire sure why $cast not returning 1. can see, i'm printing out extended class data item after casting uvm_info. can see it's being cast properly. if don't use $cast if condition, don't runtime error. isn't coding practice use if dynamic cast check if $cast returning 1 ? what might reason behind cast not returning 1 in above case? i think semicolon on line 'if' not belong? i think consumes if statement, , uvm_error executes regardless of how if evaluates: if(!$cast(data_ext, data)); <- no semico...
Read more

ios - Change Storyboard View using Seague -

i have following code checks connection server, , depending on want change views if no connection found. nsstring *connect = [nsstring stringwithcontentsofurl:[nsurl urlwithstring:@"http://myserver.com"] encoding:nsutf8stringencoding error:nil]; if (connect == null) { [self performseguewithidentifier:@"network_failure" sender:self]; } else { // other code here } my problem not change views. have added storyboard segue between 2 views identifier of network_failure . not have navigation controller or that, problem? thanks help! no not problem. first of all, in objectivec exists nil object oriented null . must use that. so: if(connect == nil) or better: if(!connect) so due fact nil not same of null , probably code does't enter in if scope . you have been able discover breakpoint. anyway: be sure set trigger segue (line) 2 view controller , , name network_failure (that not best name. should instead view1toview2 ) as, m...
Read more