Info: SBT compilation for play framework 2.x disabled by default

 org.apache.kafka.common.config.ConfigException: Missing required configuration "bootstrap.servers" which has no default value.

org.apache.kafka.common.config.ConfigException: Missing required configuration "key.serializer" which has no default value.

Properties properties = new Properties();

properties.put("client.id", "5");

properties.put("bootstrap.servers", "127.0.0.1:9092");

properties.put("request.timeout.ms", String.valueOf(timeout));

roperties.put("request.required.acks", String.valueOf(requestRequiredAcks));

properties.put("value.serializer", MyDocumentSerializer.class.getName());

properties.put("key.serializer", MyIntegerSerializer.class.getName());

properties.put("serializer.class", MyDocumentSerializer.class.getName());

properties.put("partitioner.class", MyPartitioner.class.getName());

KafkaProducer<String, Document> producer = new KafkaProducer<>(properties);

Properties props = new Properties();

props.put("group.id", "1");

props.put("zookeeper.connect", "localhost:2185");

props.put("zookeeper.session.timeout.ms", "4000");

props.put("zookeeper.sync.time.ms", "200");

props.put("auto.commit.interval.ms", "1000");

props.put("autocommit.enable", true);

ConsumerConfig consumerConfig = new ConsumerConfig(props);

ConsumerConnector consumer = Consumer.createJavaConsumerConnector(consumerConfig);

scala> List(1, "x").flatten

<console>:12: error: No implicit view available from Any => scala.collection.GenTraversableOnce[B].

       List(1, "x").flatten

scala> List(1, "x").flatMap(a => a)

<console>:12: error: type mismatch;

 found   : Any

 required: scala.collection.GenTraversableOnce[?]

       List(1, "x").flatMap(a => a)

                                 ^

scala> List(Some(1), Some("x"), None).flatten

res9: List[Any] = List(1, x)

scala> List(1, "x").flatMap(a => Some(a))

res8: List[Any] = List(1, x)

# A comma seperated list of directories under which to store log files

log.dirs=/tmp/kafka-logs

// stop

 rm -rf /tmp/kafka-logs

// start

https://www.quora.com/What-is-the-difference-between-fine-grained-and-coarse-grained-transformation-in-context-of-Spark

If there is a dataset with a billion rows, A fine grained transaction is one applied on smaller set, may be a single row.

A coarse grained one is an operation applied on an entire dataset. 

1787821114291 service 15 birthday {"result":true,"birth":"0224","id":"15","action":"add"}  2011-02-23

select * from googleplus_reqlog where date_id='2011-02-23' and label='birthday' and get_json_object(props, '$.id')='15';

CREATE VIEW `stat`.`birthday` COMMENT 'google plus birthday' AS SELECT

`birthday_temp`.`ts` AS `ts`,

`birthday_temp`.`date_id` AS `date_id`,

`birthday_temp`.`result` AS `result`,

`birthday_temp`.`birth` AS `birth`,

`birthday_temp`.`id` AS `id`,

`birthday_temp`.`action` AS `action`,

`birthday_temp`.`from` AS `from`

FROM (

  select

    ts,

    date_id,

    get_json_object(`googleplus_reqlog`.`props`, '$.result') as result,

    get_json_object(`googleplus_reqlog`.`props`, '$.birth') as birth,

    get_json_object(`googleplus_reqlog`.`props`, '$.id') as id,

    get_json_object(`googleplus_reqlog`.`props`, '$.action') as action,

  from `src`.`googleplus_reqlog`

  where label='birthday') `birthday_temp`;

hive> desc birthday;

OK

ts                   bigint

date_id             string

result               string

birth               string

id           string

action               string

 select * from birthday where date_id='2011-02-23' and account_id='15';

select * from googleplus_reqlog where date_id='2011-02-23' and label='birthday' and get_json_object(props, '$.id')='15';

The identifier quote character is the backtick (`):

mysql> SELECT * FROM `select` WHERE `select`.id > 100;

 Any column name that is specified within backticks (`) is treated literally. 

$ netstat -anp | grep LISTEN

tcp        0      0 172.17.64.41:7077           0.0.0.0:*                   LISTEN      26464/java

tcp        0      0 0.0.0.0:51047               0.0.0.0:*                   LISTEN      13816/java

...

$ lsof +c10  -iTCP -sTCP:LISTEN

COMMAND      PID   USER   FD   TYPE    DEVICE SIZE/OFF NODE NAME

java        1627 www   15u  IPv4 605880628      0t0  TCP *:41384 (LISTEN)

java        1627 www   30u  IPv4 605880676      0t0  TCP *:36194 (LISTEN)

scala> List(8, 9, 10)(0)

res5: Int = 8

scala> List(8, 9, 10)(3)

java.lang.IndexOutOfBoundsException: 3

  at scala.collection.LinearSeqOptimized$class.apply(LinearSeqOptimized.scala:65)

  at scala.collection.immutable.List.apply(List.scala:84)

  ... 48 elided

scala> List(8, 9, 10).lift

res0: Int => Option[Int] = <function1>

scala> List(8, 9, 10).lift(1)

res1: Option[Int] = Some(9)

scala> List(8, 9, 10).lift(2)

res2: Option[Int] = Some(10)

scala> List(8, 9, 10).lift(3)

res3: Option[Int] = None

scala> List(8, 9, 10).lift(4)

res4: Option[Int] = None

scala> List(8, 9, 10).lift(10).getOrElse(0).toInt

res10: Int = 0

scala> List(8, 9, 10).lift(1).getOrElse(0).toInt

res11: Int = 9

scala> val test: PartialFunction[Int, Int] = { case i if i == 0 => 0 ; case _ => -1}

test: PartialFunction[Int,Int] = <function1>

scala> test.lift(0)

res15: Option[Int] = Some(0)

scala> test.lift(11)

res16: Option[Int] = Some(-1)

ByteBuffer.allocate(4).putInt(data).array();

import org.apache.commons.lang.SerializationUtils;

SerializationUtils.serialize(data);

    public static byte[] serialize(Serializable obj) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream(512);

        serialize(obj, baos);

        return baos.toByteArray();

    }