4 Automatic Heartbeat for Big Data

This chapter describes how to enable Heartbeat for Oracle GoldenGate for Big Data and how to manage and modify heartbeat across the replication environment.

• Overview
  
• Automatic Heartbeat Tables
  

4.1 Overview

To enable HEARTBEATTABLE for Oracle GoldenGate for BigData, you need to:

• Specify GGSCHEMA in GLOBALS with any value, for example, GGSCHEMA GGADMIN.
• Execute ADD HEARTBEATTABLE from GGSCI.

In Oracle GoldenGate for RDBMS, the HEARTBEATTABLE records are applied to the following target HEARTBEATTABLE tables: GGADMIN.GG_HEARTBEAT and GGADMIN.GG_HEARBEAT_HISTORY.

Two Modes of HEARTBEATTABLE in Oracle GoldenGate for Big Data

In mode1, the records that are handled by Oracle GoldenGate for Big Data are written to HEARTBEATTABLE files. For example,

Table GGADMIN.GG_HEARTBEAT is stored in file dirtmp/<replicat name>-hb.json. Here, the records are written to the replicat file hb.json.

Table GGADMIN.GG_HEARTBEAT_HISTORY is stored in dirtmp/<replicat-name>-hb-<date>.json. Here, the History records re written to the hb-<date>.json file.

Mode 2 is passthrough that enables you to send a statement directly to a non-Oracle system, such as Kafka without first being interpreted by Big Data.

To apply HEARTBEATTABLE as user data:

• Disable HEARTBEATTABLE by specifying DISABLEHEARTBEATTABLE in the replicat parameter file.
• Specify HEARTBEATTABLE tables in the replicat MAP statements:

  MAP GGADMIN.GG_HEARTBEAT, TARGET
  GGADMIN.GG_HEARTBEAT;
  MAP GGADMIN.GG_HEARTBEAT_HISTORY, TARGET
  GGADMIN.GG_HEARTBEAT_HISTORY;

  When applied as user data, the HEARTBEAT records GG_HEARTBEAT and GG_HEARTBEAT_HISTORY are written to the handler as if they are user tables. The HEARTBEAT records are not stored in tables like RDBMS, but in .json files.

4.2 Automatic Heartbeat Tables

• ADD HEARTBEATTABLE
  
• ALTER HEARTBEAT TABLE
  
• INFO HEARTBEATTABLE
  
• LAG
  
• DELETE HEARTBEATTABLE
  

4.2.1 ADD HEARTBEATTABLE

ADD HEARTBEATTABLE
[, RETENTION_TIME number in days] |
[, PURGE_FREQUENCY number in days]

RETENTION_TIME

Specifies when heartbeat entries older than the retention time in the history table are purged. The default is 30 days.

PURGE FREQUENCY

Specifies how often the purge scheduler is run to delete table entries that are older than the retention time from the heartbeat history. The default is 1 day.

Example:

GGSCI > ADD HEARTBEATTABLE
HEARTBEAT is now enabled:
HEARTBEAT configuration file in dirprm\heartbeat.properties
heartbeat.enabled=true
heartbeat.frequency=60
heartbeat.retention_time=30
heartbeat.purge.frequency=1
heartbeat.db.name=BigData

4.2.2 ALTER HEARTBEAT TABLE

ALTER HEARTBEATTABLE

[, RETENTION_TIME number in days] |

[, PURGE_FREQUENCY number in days]

RETENTION_TIME

Update heartbeat.retention_time in dirprm/heartbeat.properties; will take affect on the next restart.

PURGE_FREQUENCY

Specifies how often entries older than the retention time are purged from the GG_HEARTBEAT_HISTORY. The default is 1 day.

4.2.3 INFO HEARTBEATTABLE

Example

HEARTBEAT configuration file dirprm\heartbeat.properties
heartbeat.enabled=true
heartbeat.frequency=60
heartbeat.retention_time=30
heartbeat.purge.frequency=1
heartbeat.db.name=BigData

4.2.4 LAG

LAG <replicat name>

Example

GGSCI> LAG rtpc
Lag Information From Heartbeat Table
LAG                 AGE                 FROM       TO         PATH
5.77s               10m 22.87s          ORCL       BIGDATA    ETPC ==> PTPC ==> RTPC

LAG <replicat name> HISTORY

GGSCI> LAG rtpc HISTORY

Example

Lag Information From Heartbeat Table 
LAG      AGE          FROM       TO      PATH 
5.77s   10m 22.87s    ORCL       ORCL    ETPC ==> PTPC ==> RTPC 
Lag History 
DATE         MIN        AVG        MAX
2018-07-01   5.77s      5.90s      6.20s 
2018-07-02   6.77s      6.90s      7.20s 
2018-07-03   7.77s      7.90s      8.20s 
2018-07-04   8.77s      9.90s      9.20s

4.2.5 DELETE HEARTBEATTABLE

DELETE HEARTBEATTABLE

Example

GGSCI> DELETE HEARTBEATTABLE