Control Center (Confluent3) is not reachable on port 9021

[Vadim Dzyuban]

I followed the instructions at http://docs.confluent.io/3.0.0/control-center/docs/quickstart.html,

successfully started zookeeper, kafka, schema registry, kafka connect, control center, all 10) steps until 11) . 

There were no errors on the console outputs. 

Unfortunately I CAN'T ACCESS CONTROL CENTER WEB UI ON PORT 9021.

I got "The site can't be reached, refused to connect" on the browser at http://xyz:9021

Below are some details and I would appreciate for any help or idea why it is not working.

Environment:  confluent 3 on centos 7 + java 8

(1)running "wget" on port 9021 refused to connect:

 wget 127.0.0.1:9021

--2016-07-22 15:18:20--  http://127.0.0.1:9021/

Connecting to 127.0.0.1:9021... failed: Connection refused.

(2)"wget" on port 8083 is ok:

wget 127.0.0.1:8083

--2016-07-22 15:20:19--  http://127.0.0.1:8083/

Connecting to 127.0.0.1:8083... connected.

HTTP request sent, awaiting response... 200 OK

Length: 54 [application/json]

Saving to: ‘index.html.7’

100%[==============================================================================================================================================================>] 54          --.-K/s   in 0s

2016-07-22 15:20:19 (8.40 MB/s) - ‘index.html.7’ saved [54/54]

(3)console output when starting control center looks ok:

./usr/bin/control-center-start /tmp/control-center.properties

SLF4J: Class path contains multiple SLF4J bindings.

SLF4J: Found binding in [jar:file:/usr/share/java/confluent-common/slf4j-log4j12-1.7.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: Found binding in [jar:file:/usr/share/java/confluent-control-center/slf4j-log4j12-1.7.21.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.

SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]

Internal topics already exist. OK.

SLF4J: Class path contains multiple SLF4J bindings.

SLF4J: Found binding in [jar:file:/usr/share/java/confluent-common/slf4j-log4j12-1.7.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: Found binding in [jar:file:/usr/share/java/confluent-control-center/slf4j-log4j12-1.7.21.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.

SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]

[2016-07-22 14:40:37,510] INFO ControlCenterConfig values:

        confluent.controlcenter.internal.topics.replication = 1

        compression.type = lz4

        metric.reporters = []

        ssl.client.auth = false

        bootstrap.servers = [localhost:9092]

        response.mediatype.default = application/json

        confluent.controlcenter.data.dir = /tmp/confluent/control-center

        retry.backoff.ms = 100

        ssl.keystore.type = JKS

        ssl.trustmanager.algorithm =

        metrics.jmx.prefix = confluent.controlcenter

        confluent.controlcenter.name = _confluent-controlcenter

        request.logger.name = io.confluent.rest-utils.requests

        confluent.controlcenter.license =

        ssl.key.password =

        confluent.controlcenter.connect.cluster = localhost:8083

        ssl.truststore.password =

        session.timeout.ms = 275000

        metrics.num.samples = 2

        ssl.endpoint.identification.algorithm =

        ssl.protocol = TLS

        debug = false

        listeners = []

        max.poll.records = 11

        request.timeout.ms = 285000

        ssl.provider =

        ssl.enabled.protocols = []

        shutdown.graceful.ms = 1000

        ssl.keystore.location =

        response.mediatype.preferred = [application/json]

        confluent.monitoring.interceptor.topic = _confluent-monitoring

        ssl.cipher.suites = []

        ssl.truststore.type = JKS

        confluent.controlcenter.id = 0

        retries = 2147483647

        access.control.allow.methods = GET,OPTIONS,HEAD,POST,PUT,DELETE

        access.control.allow.origin = *

        ssl.truststore.location =

        ssl.keystore.password =

        ssl.keymanager.algorithm =

        zookeeper.connect = localhost:2181

        port = 9021

        metrics.sample.window.ms = 30000

        confluent.controlcenter.streams.threads = 2

 (io.confluent.controlcenter.ControlCenterConfig:135)

[2016-07-22 14:40:38,667] WARN file=dist/index.html length=311 (io.confluent.controlcenter.rest.StaticFileResource:77)

[2016-07-22 14:40:38,732] WARN file=dist/app.js length=1811321 (io.confluent.controlcenter.rest.StaticFileResource:77)

[2016-07-22 14:40:38,736] WARN file=dist/app.css length=167621 (io.confluent.controlcenter.rest.StaticFileResource:77)

[2016-07-22 14:40:39,010] WARN checking license failure: Unable to process JOSE object (cause: org.jose4j.lang.JoseException: Invalid JOSE Compact Serialization. Expecting either 3 or 5 parts for JWS or JWE respectively but was 1.):  (io.confluent.license.LicenseModule:39)