/rds-db2

RDS for Db2 — Operations Reference

Scale compute (up/down)

aws rds modify-db-instance \
  --db-instance-identifier <instance-id> \
  --db-instance-class db.m6i.2xlarge \
  --apply-immediately

Instance classes: db.t3.* (burstable), db.m6i.* (general purpose), db.r6i.* (memory optimized), db.x2iedn.* (memory optimized, up to 128 vCPU / 4 TiB RAM).

Scaling compute causes a brief outage (Multi-AZ minimizes this to ~60 seconds).

Scale storage

Storage can be scaled up but not down. To reduce storage, you must create a new instance and migrate data.

aws rds modify-db-instance \
  --db-instance-identifier <instance-id> \
  --allocated-storage 500 \
  --apply-immediately

Enable storage autoscaling:

aws rds modify-db-instance \
  --db-instance-identifier <instance-id> \
  --max-allocated-storage 1000

Parameter groups

View modifiable parameters

aws rds describe-db-parameters \
  --db-parameter-group-name <param-group-name> \
  --query 'Parameters[?IsModifiable==`true`].[ParameterName,ParameterValue,Description]' \
  --output table

Modify a parameter

aws rds modify-db-parameter-group \
  --db-parameter-group-name <param-group-name> \
  --parameters "ParameterName=<name>,ParameterValue=<value>,ApplyMethod=immediate"

Non-modifiable instance-level parameters

Parameters that are managed by RDS and cannot be changed:

• db2comm (always TCPIP)
• svcename (managed by RDS)
• diagpath (managed by RDS)
• notifylevel (managed by RDS)
• Instance owner and home directory settings

Find Db2 registry variables modifiable in RDS

-- Connect to RDSADMIN
SELECT name, value, deferred
FROM TABLE(rdsadmin.list_db_registry_variables()) AS t;

Modify a registry variable:

call rdsadmin.set_db_registry_variable('<VAR_NAME>', '<VALUE>');

RDSADMIN stored procedures

Key stored procedures available to the master user:

Load data from S3

RDS for Db2 supports loading data directly from S3 using DB2REMOTE identifiers.

Create storage access alias

-- On RDS for Db2 (IAM role handles auth — no credentials needed):
db2 "CATALOG STORAGE ACCESS ALIAS myS3 VENDOR S3 
     SERVER https://s3.<region>.amazonaws.com 
     CONTAINER <bucket-name> 
     DBUSER <masterUserName>"

Load from S3

CALL SYSPROC.ADMIN_CMD('LOAD FROM DB2REMOTE://myS3/<path/to/file.ixf> OF IXF INSERT INTO <schema>.<table>');

Or using LOAD CLIENT from a connected Db2 client:

db2 "LOAD CLIENT FROM /local/path/file.ixf OF IXF INSERT INTO <schema>.<table>"

Monitoring

Enable Enhanced Monitoring

aws rds modify-db-instance \
  --db-instance-identifier <instance-id> \
  --monitoring-interval 60 \
  --monitoring-role-arn arn:aws:iam::<account>:role/rds-monitoring-role

Enhanced monitoring data goes to CloudWatch Logs group RDSOSMetrics. Metrics include CPU, memory, disk I/O, network at OS level (1–60 second granularity).

Enable db2diag logs to CloudWatch

aws rds modify-db-instance \
  --db-instance-identifier <instance-id> \
  --cloudwatch-logs-export-configuration '{"EnableLogTypes":["diag"]}'

Logs appear in CloudWatch Logs group /aws/rds/instance/<instance-id>/diag.

Encrypt the log group. db2diag logs can contain sensitive diagnostic data, so encrypt the CloudWatch Logs group with a KMS key:

aws logs associate-kms-key \
  --log-group-name /aws/rds/instance/<instance-id>/diag \
  --kms-key-id <kms-key-arn>

Download db2diag logs to laptop

# List available log files
aws rds describe-db-log-files \
  --db-instance-identifier <instance-id>

# Download a specific log file
aws rds download-db-log-file-portion \
  --db-instance-identifier <instance-id> \
  --log-file-name <log-file-name> \
  --output text > db2diag.log

Create CloudWatch dashboard from Enhanced Monitoring

Enhanced monitoring data is in CloudWatch Logs (not CloudWatch Metrics directly). Use CloudWatch Logs Insights to query and build dashboards:

fields @timestamp, cpuUtilization.total, memory.free
| filter @logStream like /RDSOSMetrics/
| sort @timestamp desc
| limit 100

Or use the RDS console → Monitoring tab → Enhanced monitoring for a built-in view.

Run basic monitoring from Db2 client

-- Active connections
SELECT application_name, application_id, connection_start_time
FROM TABLE(MON_GET_CONNECTION(CAST(NULL AS BIGINT), -1)) AS t;

-- Database memory usage
SELECT pool_id, pool_cur_size, pool_config_size
FROM TABLE(MON_GET_MEMORY_POOL(NULL, -1)) AS t;

-- Top SQL by CPU
SELECT substr(stmt_text,1,80) AS sql, total_cpu_time, num_executions
FROM TABLE(MON_GET_PKG_CACHE_STMT(NULL, NULL, NULL, -1)) AS t
ORDER BY total_cpu_time DESC FETCH FIRST 10 ROWS ONLY;

Enable Audit

RDS for Db2 audit logging is configured through an RDS option group with the DB2_AUDIT option (backed by an IAM role and an S3 bucket), followed by the in-database CREATE AUDIT POLICY / AUDIT DATABASE USING POLICY flow. For the full sourced procedure, see db2-audit.md.

Performance benchmarks with HammerDB

Source: https://aws.amazon.com/blogs/database/use-hammerdb-to-run-performance-tests-on-amazon-rds-for-db2/

HammerDB supports TPC-C and TPC-H workloads against Db2. Install HammerDB on an EC2 instance in the same VPC as the RDS instance. Configure the Db2 driver with the RDS endpoint, port, and credentials. Run TPC-C for OLTP benchmarks and TPC-H for analytical workloads.

Enable standby replica (see ha-dr.md)

See ha-dr.md for full standby replica setup.

Enable read replica

RDS for Db2 supports read replicas as a separate feature for offloading read workloads. See ha-dr.md for details. Note that standby replicas (DR replicas in mounted/HADR mode) cannot serve reads while in standby mode.