背景
在大資料時代，存在大量基于資料的業務。資料需要在不同的系統之間流動、整合。通常，核心業務系統的資料存在OLTP資料庫系統中，其它業務系統需要擷取OLTP系統中的資料。傳統的數倉通過批量資料同步的方式，定期從OLTP系統中抽取資料。但是随着業務需求的更新，批量同步無論從實時性，還是對線上OLTP系統的抽取壓力，都無法滿足要求。需要實時從OLTP系統中擷取資料變更，實時同步到下遊業務系統。
本文基于Oracle OGG，介紹一種将Oracle資料庫的資料實時同步到Kafka消息隊列的方法。
Kafka是一種高效的消息隊列實作，通過訂閱kafka的消息隊列，下遊系統可以實時擷取線上Oracle系統的資料變更情況，實作業務系統。
環境介紹
元件版本
整體架構圖
名詞解釋
1.OGG Manager
OGG Manager用于配置和管理其它OGG元件，配置資料抽取、資料推送、資料複制，啟動和停止相關元件，檢視相關元件的運作情況。
2.資料抽取（Extract）
抽取源端資料庫的變更（DML, DDL）。資料抽取主要分如下幾種類型：
本地抽取
從本地資料庫捕獲增量變更資料，寫入到本地Trail檔案
資料推送（Data Pump）
從本地Trail檔案讀取資料，推送到目标端。
初始資料抽取
從資料庫表中導出全量資料，用于初次資料加載
3.資料推送（Data Pump）
Data Pump是一種特殊的資料抽取（Extract）類型，從本地Trail檔案中讀取資料，并通過網絡将資料發送到目标端OGG
4.Trail檔案
資料抽取從源端資料庫抓取到的事物變更資訊會寫入到Trail檔案。
5.資料接收（Collector）
資料接收程式運作在目标端機器，用于接收Data Pump發送過來的Trail日志，并将資料寫入到本地Trail檔案。
6.資料複制（Replicat）
資料複制運作在目标端機器，從Trail檔案讀取資料變更，并将變更資料應用到目标端資料存儲系統。本案例中，資料複制将資料推送到kafka消息隊列。
7.檢查點（Checkpoint）
檢查點用于記錄資料庫事物變更。
操作步驟
源端Oracle配置
1.檢查歸檔
使用OGG，需要在源端開啟歸檔日志
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u01/app/oracle/product/12.2.0/db_1/dbs/arch
Oldest online log sequence 2576
Next log sequence to archive 2577
Current log sequence 2577
2.檢查資料庫配置
SQL> select force_logging, supplemental_log_data_min from v$database;
FORCE_LOGG SUPPLEMENTAL_LOG_DATA_MI
---------- ------------------------
YES YES
如果沒有開啟輔助日志，需要開啟：
SQL> alter database force logging;
SQL> alter database add supplemental log data;
3.開啟goldengate複制參數
SQL> alter system set enable_goldengate_replication = true;
4.建立源端Oracle賬号
SQL> create tablespace tbs_ogg datafile '/oradata/dtstack/tbs_ogg.dbf' size 1024M autoextend on;
SQL> create user ggsadmin identified by oracle default tablespace tbs_ogg;
SQL> grant dba to ggsadmin;
5.建立測試表
SQL> create table baiyang.ora_to_kfk as select OWNER, OBJECT_NAME, SUBOBJECT_NAME, OBJECT_ID, DATA_OBJECT_ID, OBJECT_TYPE from all_objects where object_id < 500;
SQL> alter table baiyang.ora_to_kfk add constraint pk_kfk_obj primary key(object_id);
SQL> select count(*) from baiyang.ora_to_kfk;
COUNT(*)
----------
436
源端OGG配置
1.檢查源端OGG環境
cd /oradata/oggorcl/ogg
./ggsci
GGSCI (dtproxy) 1> info all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER STOPPED
2.建立相關檔案夾
GGSCI (dtproxy) 2> create subdirs
Creating subdirectories under current directory /oradata/oggorcl/ogg
Parameter file /oradata/oggorcl/ogg/dirprm: created.
Report file /oradata/oggorcl/ogg/dirrpt: created.
Checkpoint file /oradata/oggorcl/ogg/dirchk: created.
Process status files /oradata/oggorcl/ogg/dirpcs: created.
SQL script files /oradata/oggorcl/ogg/dirsql: created.
Database definitions files /oradata/oggorcl/ogg/dirdef: created.
Extract data files /oradata/oggorcl/ogg/dirdat: created.
Temporary files /oradata/oggorcl/ogg/dirtmp: created.
Credential store files /oradata/oggorcl/ogg/dircrd: created.
Masterkey wallet files /oradata/oggorcl/ogg/dirwlt: created.
Dump files /oradata/oggorcl/ogg/dirdmp: created.
3.配置源端Manager
GGSCI (dtproxy) 4> dblogin userid ggsadmin password oracle
Successfully logged into database.
GGSCI (dtproxy as [email protected]) 5> edit param ./globals
-- 添加
oggschema ggsadmin
GGSCI (dtproxy as [email protected]) 6> edit param mgr
-- 添加
PORT 7810 --預設監聽端口
DYNAMICPORTLIST 7811-7820 --動态端口清單
AUTORESTART EXTRACT *,RETRIES 5,WAITMINUTES 3 --程序有問題，每3分鐘重新開機一次，一共重新開機五次
PURGEOLDEXTRACTS ./dirdat
LAGREPORTHOURS 1 --每隔一小時檢查一次傳輸延遲情況
LAGINFOMINUTES 30 --傳輸延時超過30分鐘将寫入錯誤日志
LAGCRITICALMINUTES 45 --傳輸延時超過45分鐘将寫入警告日志
PURGEMARKERHISTORY MINKEEPDAYS 3, MAXKEEPDAYS 7 --定期清理trail檔案
ACCESSRULE, PROG *, IPADDR 172.*.*.*, ALLOW --設定172網段可連接配接
-- 添加同步的表
GGSCI (dtproxy as [email protected]) 9> add trandata baiyang.ora_to_kfk
-- Oracle Goldengate marked following column as key columns on table BAIYANG.ORA_TO_KFK: OBJECT_ID.
GGSCI (dtproxy as [email protected]) 10> info trandata baiyang.ora_to_kfk
-- Prepared CSN for table BAIYANG.ORA_TO_KFK: 192881239
目标端OGG配置
1.目标端檢查環境
GGSCI (172-16-101-242) 1> info all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER STOPPED
2.建立目錄
GGSCI (172-16-101-242) 2> create subdirs
Creating subdirectories under current directory /app/ogg
Parameter file /app/ogg/dirprm: created.
Report file /app/ogg/dirrpt: created.
Checkpoint file /app/ogg/dirchk: created.
Process status files /app/ogg/dirpcs: created.
SQL script files /app/ogg/dirsql: created.
Database definitions files /app/ogg/dirdef: created.
Extract data files /app/ogg/dirdat: created.
Temporary files /app/ogg/dirtmp: created.
Credential store files /app/ogg/dircrd: created.
Masterkey wallet files /app/ogg/dirwlt: created.
Dump files /app/ogg/dirdmp: created.
3.目标端Manager配置
GGSCI (172-16-101-242) 3> edit params mgr
-- 添加
PORT 7810
DYNAMICPORTLIST 7811-7820
AUTORESTART EXTRACT *,RETRIES 5,WAITMINUTES 3
PURGEOLDEXTRACTS ./dirdat
vi custom_kafka_producer.properties
-- 添加
bootstrap.servers=172.16.101.242:9092
acks=1
compression.type=gzip
reconnect.backoff.ms=1000
value.serializer=org.apache.kafka.common.serialization.ByteArraySerializer
key.serializer=org.apache.kafka.common.serialization.ByteArraySerializer
batch.size=102400
linger.ms=10000
5.源端開啟全量資料抽取
-- 源端
GGSCI (dtproxy) 20> start mgr
GGSCI (dtproxy) 21> start initkfk
6.目标端全量資料應用
GGSCI (172-16-101-242) 13> start mgr
./replicat paramfile ./dirprm/initkfk.prm reportfile ./dirrpt/init01.rpt -p INITIALDATALOAD
7.kafka資料驗證
使用kafka用戶端工具檢視topic的資料
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test_ogg --from-beginning
{"table":"BAIYANG.ORA_TO_KFK","op_type":"I","op_ts":"2019-11-11 20:23:19.703779","current_ts":"2019-11-11T20:48:55.946000","pos":"-0000000000000000001","after":{"OWNER":"SYS","OBJECT_NAME":"C_OBJ#","SUBOBJECT_NAME":null,"OBJECT_ID":2,"DATA_OBJECT_ID":2,"OBJECT_TYPE":"CLUSTER"}}
{"table":"BAIYANG.ORA_TO_KFK","op_type":"I","op_ts":"2019-11-11 20:23:19.703779","current_ts":"2019-11-11T20:48:56.289000","pos":"-0000000000000000001","after":{"OWNER":"SYS","OBJECT_NAME":"I_OBJ#","SUBOBJECT_NAME":null,"OBJECT_ID":3,"DATA_OBJECT_ID":3,"OBJECT_TYPE":"INDEX"}}
全量資料已經同步到目标kafka topic
增量資料同步
1.源端抽取程序配置
GGSCI (dtproxy) 9> edit param extkfk
-- 添加
dynamicresolution
SETENV (ORACLE_SID = "dtstack")
SETENV (NLS_LANG = "american_america.AL32UTF8")
userid ggsadmin,password oracle
exttrail ./dirdat/to
table baiyang.ora_to_kfk;
-- 添加extract程序
GGSCI (dtproxy) 10> add extract extkfk,tranlog,begin now
-- 添加trail檔案的定義與extract程序綁定
GGSCI (dtproxy) 11> add exttrail ./dirdat/to,extract extkfk
2.源端資料推送程序配置
-- 配置源端推送程序
GGSCI (dtproxy) 12> edit param pupkfk
-- 添加
extract pupkfk
passthru
dynamicresolution
userid ggsadmin,password oracle
rmthost 172.16.101.242 mgrport 7810
rmttrail ./dirdat/to
table baiyang.ora_to_kfk;
-- 添加extract程序
GGSCI (dtproxy) 13> add extract pupkfk,exttrailsource /oradata/oggorcl/ogg/dirdat/to
-- 添加trail檔案的定義與extract程序綁定
GGSCI (dtproxy) 14> add rmttrail ./dirdat/to,extract pupkfk
3.配置目标端恢複程序
-- 配置目标端恢複程序
edit param repkfk
-- 添加
REPLICAT repkfk
SOURCEDEFS ./dirdef/define_kfk.txt
targetdb libfile libggjava.so set property=./dirprm/kafka.props
REPORTCOUNT EVERY 1 MINUTES, RATE
GROUPTRANSOPS 10000
MAP baiyang.ora_to_kfk, TARGET baiyang.ora_to_kfk;
--添加trail檔案到replicate程序
add replicat repkfk exttrail ./dirdat/to,checkpointtable ggsadmin.checkpoint
4.源端開啟實時資料抓取
./ggsci
GGSCI (dtproxy) 5> start extkfk
Sending START request to MANAGER ...
EXTRACT EXTKFK starting
GGSCI (dtproxy) 6> start pupkfk
Sending START request to MANAGER ...
EXTRACT PUPKFK starting
GGSCI (dtproxy) 7> status all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER RUNNING
EXTRACT RUNNING EXTKFK 00:00:00 00:00:10
EXTRACT RUNNING PUPKFK 00:00:00 00:00:00
5.目标端開啟實時資料同步
./ggsci
GGSCI (172-16-101-242) 7> start replicat repkfk
Sending START request to MANAGER ...
REPLICAT REPKFK starting
GGSCI (172-16-101-242) 8> info all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER RUNNING
REPLICAT RUNNING REPKFK 00:00:00 00:00:00
6.測試增量資料同步
Oracle插入增量資料
SQL> insert into baiyang.ora_to_kfk select OWNER, OBJECT_NAME, SUBOBJECT_NAME, OBJECT_ID, DATA_OBJECT_ID, OBJECT_TYPE from all_objects where object_id >500 and object_id < 1000;
SQL> commit;
SQL> select count(*) from baiyang.ora_to_kfk;
COUNT(*)
----------
905
檢視Kafka消息隊列消費資料
{"table":"BAIYANG.ORA_TO_KFK","op_type":"I","op_ts":"2019-11-11 21:04:11.158786","current_ts":"2019-11-11T21:10:54.042000","pos":"00000000000000075298","after":{"OWNER":"SYS","OBJECT_NAME":"APPLY$_READER_STATS","SUBOBJECT_NAME":null,"OBJECT_ID":998,"DATA_OBJECT_ID":998,"OBJECT_TYPE":"TABLE"}}
{"table":"BAIYANG.ORA_TO_KFK","op_type":"I","op_ts":"2019-11-11 21:04:11.158786","current_ts":"2019-11-11T21:10:54.042001","pos":"00000000000000075459","after":{"OWNER":"SYS","OBJECT_NAME":"APPLY$_READER_STATS_I","SUBOBJECT_NAME":null,"OBJECT_ID":999,"DATA_OBJECT_ID":999,"OBJECT_TYPE":"INDEX"}}
源端Oracle删除資料
SQL> delete from baiyang.ora_to_kfk ;
906 rows deleted.
SQL> commit;
檢視kafka消息隊列消費資料
{"table":"BAIYANG.ORA_TO_KFK","op_type":"D","op_ts":"2019-11-11 21:13:11.166184","current_ts":"2019-11-11T21:13:17.449007","pos":"00000000000000216645","before":{"OWNER":"x1","OBJECT_NAME":"SSSSS","SUBOBJECT_NAME":"z1","OBJECT_ID":111000,"DATA_OBJECT_ID":2000,"OBJECT_TYPE":"x1"}}
源端插入資料
SQL> insert into baiyang.ora_to_kfk values('漢字', 'y1', 'z1', 111000,2000,'x1');
1 row created.
SQL> commit;
檢視kafka消息隊列消費資料
{"table":"BAIYANG.ORA_TO_KFK","op_type":"I","op_ts":"2019-11-11 21:14:21.167454","current_ts":"2019-11-11T21:14:26.497000","pos":"00000000000000216794","after":{"OWNER":"漢字","OBJECT_NAME":"y1","SUBOBJECT_NAME":"z1","OBJECT_ID":111000,"DATA_OBJECT_ID":2000,"OBJECT_TYPE":"x1"}}
總結
使用OGG可以友善地将Oracle的資料變更情況實時同步到Kafka消息隊列。下遊業務系統通過訂閱kafka的消息隊列，能友善地實作各類實時資料的應用。