Hello,

There is an issue with the docker image as it's not working out of the box.
When running the SQL CLI and trying to 'select * from Rides' I get an error:
[ERROR] Could not execute SQL statement. Reason:
java.lang.ClassCastException: cannot assign instance of java.util.concurrent.ConcurrentHashMap to field org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.deser.DeserializerCache._cachedDeserializers of type org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.util.LRUMap in instance of org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.deser.DeserializerCache

--2021-02-01 13:11:16-- https://drive.google.com/uc?export=download&id=1pf4tfv-YpoVQ9_O0948M8oXeCfVH-0MH
Resolving drive.google.com (drive.google.com)... 203.208.46.146, 74.125.71.94
Connecting to drive.google.com (drive.google.com)|203.208.46.146|:443... failed: Connection refused.
Connecting to drive.google.com (drive.google.com)|74.125.71.94|:443... failed: Connection refused.
--2021-02-01 13:11:58-- https://drive.google.com/uc?export=download&id=1SriiwcIdMvY7uJsWSY4Hhh32iO3F4ND2
Resolving drive.google.com (drive.google.com)... 203.208.46.146, 74.125.71.94
Connecting to drive.google.com (drive.google.com)|203.208.46.146|:443... failed: Connection refused.
Connecting to drive.google.com (drive.google.com)|74.125.71.94|:443... failed: Connection refused.
--2021-02-01 13:12:42-- https://drive.google.com/uc?export=download&id=1gY8W07OFvB7_4lHlAyingM4WQzs0_8lT
Resolving drive.google.com (drive.google.com)... 203.208.46.146, 74.125.71.94
Connecting to drive.google.com (drive.google.com)|203.208.46.146|:443... failed: Connection refused.
Connecting to drive.google.com (drive.google.com)|74.125.71.94|:443... failed: Connection refused.
ERROR: Service 'sql-client' failed to build : The command '/bin/sh -c wget -P /opt/sql-client/lib/ https://repo.maven.apache.org/maven2/org/apache/flink/flink-json/${FLINK_VERSION}/flink-json-${FLINK_VERSION}.jar; wget -P /opt/sql-client/lib/ https://repo.maven.apache.org/maven2/org/apache/flink/flink-sql-connector-kafka_2.11/${FLINK_VERSION}/flink-sql-connector-kafka_2.11-${FLINK_VERSION}.jar; wget -P /opt/sql-client/lib/ https://repo.maven.apache.org/maven2/org/apache/flink/flink-connector-filesystem_2.11/${FLINK_VERSION}/flink-connector-filesystem_2.11-${FLINK_VERSION}.jar; wget -P /opt/flink/lib https://repo.maven.apache.org/maven2/org/apache/flink/flink-shaded-hadoop-2-uber/2.7.5-8.0/flink-shaded-hadoop-2-uber-2.7.5-8.0.jar; wget -P /opt/sql-client/lib/ https://repo.maven.apache.org/maven2/org/apache/flink/flink-connector-jdbc_2.11/${FLINK_VERSION}/flink-connector-jdbc_2.11-${FLINK_VERSION}.jar; wget -P /opt/sql-client/lib/ https://repo.maven.apache.org/maven2/mysql/mysql-connector-java/8.0.19/mysql-connector-java-8.0.19.jar; mkdir -p /opt/data; mkdir -p /opt/data/stream; wget -O /opt/data/driverChanges.txt.gz 'https://drive.google.com/uc?export=download&id=1pf4tfv-YpoVQ9_O0948M8oXeCfVH-0MH'; wget -O /opt/data/fares.txt.gz 'https://drive.google.com/uc?export=download&id=1SriiwcIdMvY7uJsWSY4Hhh32iO3F4ND2'; wget -O /opt/data/rides.txt.gz 'https://drive.google.com/uc?export=download&id=1gY8W07OFvB7_4lHlAyingM4WQzs0_8lT';' returned a non-zero code: 4

(base) localhost:~ sunfu$ docker-compose exec sql-client ./sql-client.sh
Reading default environment from: file:/opt/sql-client/conf/config.yaml
No session environment specified.
Validating current environment...done.

[Reading default environment from: file:/opt/sql-client/conf/config.yaml] how to overwrite de config.yaml

Status: Downloaded newer image for fhueske/flink-sql-client-training-1.7.2:latest
Creating _elasticsearch_1 ... error
Creating _jobmanager_1 ...
Creating _zookeeper_1 ...

Creating jobmanager_1 ... error
[a-zA-Z0-9][a-zA-Z0-9.-] are allowed'

ERROR: for _jobmanager_1 Cannot create container for service jobmanager: b'Invalid container name (_jobmanager_1), only [a-zA-Z0Creating _zookeeper_1 ... error

ERROR: for _zookeeper_1 Cannot create container for service zookeeper: b'Invalid container name (zookeeper_1), only [a-zA-Z0-9][a-zA-Z0-9.-] are allowed'

ERROR: for elasticsearch Cannot create container for service elasticsearch: b'Invalid container name (elasticsearch_1), only [a-zA-Z0-9][a-zA-Z0-9.-] are allowed'

ERROR: for jobmanager Cannot create container for service jobmanager: b'Invalid container name (jobmanager_1), only [a-zA-Z0-9][a-zA-Z0-9.-] are allowed'

ERROR: for zookeeper Cannot create container for service zookeeper: b'Invalid container name (zookeeper_1), only [a-zA-Z0-9][a-zA-Z0-9.-] are allowed'
ERROR: Encountered errors while bringing up the project.

Average Number of Persons Leaving an Area Per Hour

SELECT
  area,
  SUM(psgSum)/24.0 AS avgPsgLeaving
FROM
  (SELECT 
     toAreaId(lon, lat) AS area,
     TUMBLE_END(rideTime ,INTERVAL '1' HOUR) AS t,
     SUM(psgCnt) AS psgSum
   FROM 
     Rides
   WHERE 
     isStart AND isInNYC(lon, lat)
   GROUP BY
     toAreaId(lon, lat),
     TUMBLE(rideTime, INTERVAL '1' HOUR))
GROUP BY
  area;

why the SUM(psgSum)/24.0 is divided by 24.
What if there were If it's only five hours, or more than 24 hours of data.
I think it is necessary to calculate how many hours between the start time and end time of all data we get from the table.
If you want to get the average of a day, you may need other restrictions to to make sure the data you get get from the table is
the same one day and complete.

When starting sql-client.sh the next error occured. OS Windows
C:\sql-training>docker-compose exec sql-client ./sql-client.sh
OCI runtime exec failed: exec failed: container_linux.go:370: starting container process caused: no such file or directory: unknown

在博客中Flink SQL 编程实践中提到了链接training-config.yaml，在最新一次提交过程中把这个文件删除了，是误操作了吗？

When sink data to External Tables, i got error:java.sql.SQLSyntaxErrorException: Table 'flinksql.AreaCnts' doesn't exist.
I just follow the tutorial: https://github.com/ververica/sql-training/wiki/Ecosystem-and-Writing-to-External-Tables#maintaining-a-continuously-updated-materialized-view-in-mysql
Did it need to create table in mysql by myself?

Environment

Deepin15.11, Docker19.03

Problem

Enter docker-compose up -d and containers can't run successfully. And container's State is Exit 1.
docker-compose logs showed me that Zookeeper has permission denied exception with sock.
It's helpless to use sudo or usermod -aG docker ${USER}.

Solution

Finally I switch Docker18.0.9, containers could run normally.

Building jobmanager
ERROR: Cannot locate specified Dockerfile: Dockerfile

When use the command
docker-compose up
for the first time , this error ocurred
ERROR: Service 'sql-client' failed to build: The command '/bin/sh -c cd /opt/sql-udfs; mvn clean install' returned a non-zero code: 1

[ERROR] Failed to execute goal on project sql-training-udfs: Could not resolve dependencies for project com.ververica.sql-training:sql-training-udfs:jar:2-FLINK-1.11_2.11: Could not transfer artifact org.apache.flink:flink-shaded-zookeeper-3:jar:3.4.14-11.0 from/to central (https://repo.maven.apache.org/maven2): GET request of: org/apache/flink/flink-shaded-zookeeper-3/3.4.14-11.0/flink-shaded-zookeeper-3-3.4.14-11.0.jar from central failed: Premature end of Content-Length delimited message body (expected: 7,712,156; received: 2,974,083) -> [Help 1]

On https://github.com/ververica/sql-training/wiki/Introduction-to-SQL-on-Flink the URLs are refering to "area-cnt":

while on https://github.com/ververica/sql-training/wiki/Ecosystem-and-Writing-to-External-Tables the URLs are refering to "area-cnts" (which is the correct one, that is actually generated).