Oracle DB Exporter

Table of Contents

Description
Installation
Running
Grafana
Troubleshooting
Operating principles

Description

A Prometheus exporter for Oracle modeled after the MySQL exporter. I'm not a DBA or seasoned Go developer so PRs definitely welcomed.

The following metrics are exposed currently.

• oracledb_exporter_last_scrape_duration_seconds
• oracledb_exporter_last_scrape_error
• oracledb_exporter_scrapes_total
• oracledb_up
• oracledb_activity_execute_count
• oracledb_activity_parse_count_total
• oracledb_activity_user_commits
• oracledb_activity_user_rollbacks
• oracledb_sessions_activity
• oracledb_wait_time_application
• oracledb_wait_time_commit
• oracledb_wait_time_concurrency
• oracledb_wait_time_configuration
• oracledb_wait_time_network
• oracledb_wait_time_other
• oracledb_wait_time_scheduler
• oracledb_wait_time_system_io
• oracledb_wait_time_user_io
• oracledb_tablespace_bytes
• oracledb_tablespace_max_bytes
• oracledb_tablespace_bytes_free
• oracledb_process_count
• oracledb_resource_current_utilization
• oracledb_resource_limit_value

Installation

Docker

You can run via Docker using an existing image. If you don't already have an Oracle server, you can run one locally in a container and then link the exporter to it.

docker run -d --name oracle -p 1521:1521 wnameless/oracle-xe-11g:16.04
docker run -d --name oracledb_exporter --link=oracle -p 9161:9161 -e DATA_SOURCE_NAME=system/oracle@oracle/xe iamseth/oracledb_exporter

Since 0.2.1, the exporter image exist with Alpine flavor. Watch out for their use. It is for the moment a test.

docker run -d --name oracledb_exporter --link=oracle -p 9161:9161 -e DATA_SOURCE_NAME=system/oracle@oracle/xe iamseth/oracledb_exporter:alpine

Binary Release

Pre-compiled versions for Linux 64 bit and Mac OSX 64 bit can be found under releases.

In order to run, you'll need the Oracle Instant Client Basic for your operating system. Only the basic version is required for execution.

Running

Ensure that the environment variable DATA_SOURCE_NAME is set correctly before starting. For Example

# export Oracle location:
export DATA_SOURCE_NAME=system/password@oracle-sid
# or using a complete url:
export DATA_SOURCE_NAME=user/password@//myhost:1521/service
# Then run the exporter
/path/to/binary/oracledb_exporter -l log.level error -l web.listen-address 9161

Usage

Usage of oracledb_exporter:
  -log.format value
       	If set use a syslog logger or JSON logging. Example: logger:syslog?appname=bob&local=7 or logger:stdout?json=true. Defaults to stderr.
  -log.level value
       	Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal].
  -custom.metrics string
        File that may contain various custom metrics in a TOML file.
  -default.metrics string
        Default TOML file metrics.
  -web.listen-address string
       	Address to listen on for web interface and telemetry. (default ":9161")
  -web.telemetry-path string
       	Path under which to expose metrics. (default "/metrics")

Default metrics

This exporter comes with a set of default metrics defined in default-metrics.toml. You can modify this file or provide a different one using default.metrics option.

Custom metrics

This exporter does not have the metrics you want? You can provide new one using TOML file. To specify this file to the exporter, you can:

• Use -custom.metrics flag followed by the TOML file
• Export CUSTOM_METRICS variable environment (export CUSTOM_METRICS=my-custom-metrics.toml)

This file must contain the following elements:

• One or several metric section ([[metric]])
• For each section a context, a request and a map between a field of your request and a comment.

Here's a simple example:

[[metric]]
context = "test"
request = "SELECT 1 as value_1, 2 as value_2 FROM DUAL"
metricsdesc = { value_1 = "Simple example returning always 1.", value_2 = "Same but returning always 2." }

This file produce the following entries in the exporter:

# HELP oracledb_test_value_1 Simple example returning always 1.
# TYPE oracledb_test_value_1 gauge
oracledb_test_value_1 1
# HELP oracledb_test_value_2 Same but returning always 2.
# TYPE oracledb_test_value_2 gauge
oracledb_test_value_2 2

You can also provide labels using labels field. Here's an example providing two metrics, with and without labels:

[[metric]]
context = "context_no_label"
request = "SELECT 1 as value_1, 2 as value_2 FROM DUAL"
metricsdesc = { value_1 = "Simple example returning always 1.", value_2 = "Same but returning always 2." }

[[metric]]
context = "context_with_labels"
labels = [ "label_1", "label_2" ]
request = "SELECT 1 as value_1, 2 as value_2, 'First label' as label_1, 'Second label' as label_2 FROM DUAL"
metricsdesc = { value_1 = "Simple example returning always 1.", value_2 = "Same but returning always 2." }

This TOML file produce the following result:

# HELP oracledb_context_no_label_value_1 Simple example returning always 1.
# TYPE oracledb_context_no_label_value_1 gauge
oracledb_context_no_label_value_1 1
# HELP oracledb_context_no_label_value_2 Same but returning always 2.
# TYPE oracledb_context_no_label_value_2 gauge
oracledb_context_no_label_value_2 2
# HELP oracledb_context_with_labels_value_1 Simple example returning always 1.
# TYPE oracledb_context_with_labels_value_1 gauge
oracledb_context_with_labels_value_1{label_1="First label",label_2="Second label"} 1
# HELP oracledb_context_with_labels_value_2 Same but returning always 2.
# TYPE oracledb_context_with_labels_value_2 gauge
oracledb_context_with_labels_value_2{label_1="First label",label_2="Second label"} 2

Last, you can set metric type using metricstype field.

[[metric]]
context = "context_with_labels"
labels = [ "label_1", "label_2" ]
request = "SELECT 1 as value_1, 2 as value_2, 'First label' as label_1, 'Second label' as label_2 FROM DUAL"
metricsdesc = { value_1 = "Simple example returning always 1 as counter.", value_2 = "Same but returning always 2 as gauge." }
# Can be counter or gauge (default)
metricstype = { value_1 = "counter" }

This TOML file will produce the following result:

# HELP oracledb_test_value_1 Simple test example returning always 1 as counter.
# TYPE oracledb_test_value_1 counter
oracledb_test_value_1 1
# HELP oracledb_test_value_2 Same test but returning always 2 as gauge.
# TYPE oracledb_test_value_2 gauge
oracledb_test_value_2 2

Customize metrics in a docker image

If you run the exporter as a docker image and want to customize the metrics, you can use the following example:

FROM iamseth/oracledb_exporter:latest

COPY custom-metrics.toml /

ENTRYPOINT ["/oracledb_exporter", "-custom.metrics", "/custom-metrics.toml"]

Integration with Grafana

An example Grafana dashboard is available here.

Troubleshooting

Error scraping for wait_time

If you experience an error Error scraping for wait_time: sql: Scan error on column index 1: converting driver.Value type string (",01") to a float64: invalid syntax source="main.go:144" you may need to set the NLS_LANG variable.

export NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P1
export DATA_SOURCE_NAME=system/oracle@myhost
/path/to/binary -l log.level error -l web.listen-address 9161

If using Docker, set the same variable using the -e flag.