如何使用 cygnus 在 MySql 中存储数据？

Question

我已阅读有关 cygnus 工作原理的所有文档，我专门测试了 this one 成功。我也读完了this 教程，但我确定我没有正确配置一些东西。

在我创建的 cygnus_instance_1.conf 中：

CYGNUS_USER=root
CONFIG_FOLDER=/usr/cygnus/conf
CONFIG_FILE=/usr/cygnus/conf/agent_1.conf
AGENT_NAME=cygnusagent
LOGFILE_NAME=cygnus.log
ADMIN_PORT=8081

在我创建的 agent_1.conf 中：

#=============================================
# To be put in APACHE_FLUME_HOME/conf/cygnus.conf
#
# General configuration template explaining how to setup a sink of each of the available types (HDFS, CKAN, MySQL).

#=============================================
# The next tree fields set the sources, sinks and channels used by Cygnus. You could use different names than the
# ones suggested below, but in that case make sure you keep coherence in properties names along the configuration file.
# Regarding sinks, you can use multiple types at the same time; the only requirement is to provide a channel for each
# one of them (this example shows how to configure 3 sink types at the same time). Even, you can define more than one
# sink of the same type and sharing the channel in order to improve the performance (this is like having
# multi-threading).
cygnusagent.sources = http-source
cygnusagent.sinks = hdfs-sink mysql-sink ckan-sink
cygnusagent.channels = hdfs-channel mysql-channel ckan-channel

#=============================================
# source configuration
# channel name where to write the notification events
cygnusagent.sources.http-source.channels = hdfs-channel mysql-channel ckan-channel
# source class, must not be changed
cygnusagent.sources.http-source.type = org.apache.flume.source.http.HTTPSource
# listening port the Flume source will use for receiving incoming notifications
cygnusagent.sources.http-source.port = 5050
# Flume handler that will parse the notifications, must not be changed
cygnusagent.sources.http-source.handler = es.tid.fiware.fiwareconnectors.cygnus.handlers.OrionRestHandler
# URL target
cygnusagent.sources.http-source.handler.notification_target = /notify
# Default service (service semantic depends on the persistence sink)
cygnusagent.sources.http-source.handler.default_service = def_serv
# Default service path (service path semantic depends on the persistence sink)
cygnusagent.sources.http-source.handler.default_service_path = def_servpath
# Number of channel re-injection retries before a Flume event is definitely discarded (-1 means infinite retries)
cygnusagent.sources.http-source.handler.events_ttl = 10
# Source interceptors, do not change
cygnusagent.sources.http-source.interceptors = ts de
# Interceptor type, do not change
cygnusagent.sources.http-source.interceptors.ts.type = timestamp
# Destination extractor interceptor, do not change
cygnusagent.sources.http-source.interceptors.de.type = es.tid.fiware.fiwareconnectors.cygnus.interceptors.DestinationExtractor$Builder
# Matching table for the destination extractor interceptor, put the right absolute path to the file if necessary
# See the doc/design/interceptors document for more details
cygnusagent.sources.http-source.interceptors.de.matching_table = /usr/cygnus/conf/matching_table.conf

# ============================================
# OrionHDFSSink configuration
# channel name from where to read notification events
cygnusagent.sinks.hdfs-sink.channel = hdfs-channel
# sink class, must not be changed
cygnusagent.sinks.hdfs-sink.type = es.tid.fiware.fiwareconnectors.cygnus.sinks.OrionHDFSSink
# Comma-separated list of FQDN/IP address regarding the Cosmos Namenode endpoints
# If you are using Kerberos authentication, then the usage of FQDNs instead of IP addresses is mandatory
cygnusagent.sinks.hdfs-sink.cosmos_host = x1.y1.z1.w1,x2.y2.z2.w2
# port of the Cosmos service listening for persistence operations; 14000 for httpfs, 50070 for webhdfs and free choice for inifinty
cygnusagent.sinks.hdfs-sink.cosmos_port = 14000
# default username allowed to write in HDFS
cygnusagent.sinks.hdfs-sink.cosmos_default_username = cosmos_username
# default password for the default username
cygnusagent.sinks.hdfs-sink.cosmos_default_password = xxxxxxxxxxxxx
# HDFS backend type (webhdfs, httpfs or infinity)
cygnusagent.sinks.hdfs-sink.hdfs_api = httpfs
# how the attributes are stored, either per row either per column (row, column)
cygnusagent.sinks.hdfs-sink.attr_persistence = column
# Hive FQDN/IP address of the Hive server
cygnusagent.sinks.hdfs-sink.hive_host = x.y.z.w
# Hive port for Hive external table provisioning
cygnusagent.sinks.hdfs-sink.hive_port = 10000
# Kerberos-based authentication enabling
cygnusagent.sinks.hdfs-sink.krb5_auth = false
# Kerberos username
cygnusagent.sinks.hdfs-sink.krb5_auth.krb5_user = krb5_username
# Kerberos password
cygnusagent.sinks.hdfs-sink.krb5_auth.krb5_password = xxxxxxxxxxxxx
# Kerberos login file
cygnusagent.sinks.hdfs-sink.krb5_auth.krb5_login_conf_file = /usr/cygnus/conf/krb5_login.conf
# Kerberos configuration file
cygnusagent.sinks.hdfs-sink.krb5_auth.krb5_conf_file = /usr/cygnus/conf/krb5.conf

# ============================================
# OrionCKANSink configuration
# channel name from where to read notification events
cygnusagent.sinks.ckan-sink.channel = ckan-channel
# sink class, must not be changed
cygnusagent.sinks.ckan-sink.type = es.tid.fiware.fiwareconnectors.cygnus.sinks.OrionCKANSink
# the CKAN API key to use
cygnusagent.sinks.ckan-sink.api_key = ckanapikey
# the FQDN/IP address for the CKAN API endpoint
cygnusagent.sinks.ckan-sink.ckan_host = x.y.z.w
# the port for the CKAN API endpoint
cygnusagent.sinks.ckan-sink.ckan_port = 80
# Orion URL used to compose the resource URL with the convenience operation URL to query it
cygnusagent.sinks.ckan-sink.orion_url = http://localhost:1026
# how the attributes are stored, either per row either per column (row, column)
cygnusagent.sinks.ckan-sink.attr_persistence = row
# enable SSL for secure Http transportation; 'true' or 'false'
cygnusagent.sinks.ckan-sink.ssl = false

# ============================================
# OrionMySQLSink configuration
# channel name from where to read notification events
cygnusagent.sinks.mysql-sink.channel = mysql-channel
# sink class, must not be changed
cygnusagent.sinks.mysql-sink.type = es.tid.fiware.fiwareconnectors.cygnus.sinks.OrionMySQLSink
# the FQDN/IP address where the MySQL server runs 
cygnusagent.sinks.mysql-sink.mysql_host = localhost
# the port where the MySQL server listes for incomming connections
cygnusagent.sinks.mysql-sink.mysql_port = 3306
# a valid user in the MySQL server
cygnusagent.sinks.mysql-sink.mysql_username = root
# password for the user above
cygnusagent.sinks.mysql-sink.mysql_password = klasika
# how the attributes are stored, either per row either per column (row, column)
cygnusagent.sinks.mysql-sink.attr_persistence = column

#=============================================
# hdfs-channel configuration
# channel type (must not be changed)
cygnusagent.channels.hdfs-channel.type = memory
# capacity of the channel
cygnusagent.channels.hdfs-channel.capacity = 1000
# amount of bytes that can be sent per transaction
cygnusagent.channels.hdfs-channel.transactionCapacity = 100

#=============================================
# ckan-channel configuration
# channel type (must not be changed)
cygnusagent.channels.ckan-channel.type = memory
# capacity of the channel
cygnusagent.channels.ckan-channel.capacity = 1000
# amount of bytes that can be sent per transaction
cygnusagent.channels.ckan-channel.transactionCapacity = 100

#=============================================
# mysql-channel configuration
# channel type (must not be changed)
cygnusagent.channels.mysql-channel.type = memory
# capacity of the channel
cygnusagent.channels.mysql-channel.capacity = 1000
# amount of bytes that can be sent per transaction
cygnusagent.channels.mysql-channel.transactionCapacity = 100

虽然我没有使用 OrionHDFSSink 和 OrionCKANSink，但我没有碰这些配置，因为我真的不确定我应该使用什么。

当我最终 subscribeContext 并以 cygnus @ 默认端口 5050 为目标时，我得到了正常响应，但我的数据库中没有创建任何内容

我在这里做错了什么？

Answer 1

首先，请随意删除 HDFS 和 CKAN 配置部分。在运行 Cygnus 时，您将避免与这些组件相关的不必要的日志。当然，记得删除所有对 sinks 和 channels 的引用；具体来说：

cygnusagent.sources = http-source
cygnusagent.sinks = mysql-sink
cygnusagent.channels = mysql-channel
...
cygnusagent.sources.http-source.channels = mysql-channel

其次，您的问题的答案可以在文档中找到：

在表格中，我们可以找到两个选项：

• 像往常一样修复了 8 字段行：recvTimeTs、recvTime、entityId、entityType、attrName、attrType、attrValue 和 attrMd。如果表在插入行之前不存在，则在执行时创建这些表（和数据库）。关于 attrValue，最简单的形式是，这个值只是一个字符串，但从 Orion 0.11.0 开始，它可以是 Json 对象或 Json 数组。关于attrMd，它包含Json中属性的元数据数组的字符串序列化（如果属性没有元数据，则插入一个空数组[]），
• 每个实体的属性有两列（一列用于值，另一列用于元数据），以及关于数据接收时间 (recv_time) 的附加列。 这种表（和数据库）必须在执行 Cygnus 之前提供，因为每个实体可能有不同数量的属性，并且通知必须确保通知每个属性的值。

连接器关于数据内部表示的行为由配置参数 attr_persistence 控制，其值可以是行或列。

可能是写法有问题，我认为最后一段必须以"结尾...整个值可以是行或列，其行为分别对应于上述选项".

即如果您使用的是列模式，则必须预先配置数据库和表。

有一个similar question 我更详细地解释了这种行为。

HTH！