Chapter 2. Installing and configuring the logs service

Red Hat OpenStack Platform (RHOSP) writes informational messages to specific log files; you can use these messages for troubleshooting and monitoring system events. The log collection agent Rsyslog collects logs on the client side and sends these logs to an instance of Rsyslog that is running on the server side. The server-side Rsyslog instance redirects log records to Elasticsearch for storage.

Note

You do not need to attach the individual log files to your support cases manually. The sosreport utility gathers the required logs automatically.

2.1. The centralized log system architecture and components

Monitoring tools use a client-server model with the client deployed onto the Red Hat OpenStack Platform (RHOSP) overcloud nodes. The Rsyslog service provides client-side centralized logging (CL).

All RHOSP services generate and update log files. These log files record actions, errors, warnings, and other events. In a distributed environment like OpenStack, collecting these logs in a central location simplifies debugging and administration.

With centralized logging, there is one central place to view logs across your entire RHOSP environment. These logs come from the operating system, such as syslog and audit log files, infrastructure components, such as RabbitMQ and MariaDB, and OpenStack services such as Identity, Compute, and others. The centralized logging toolchain consists of the following components:

  • Log Collection Agent (Rsyslog)
  • Data Store (ElasticSearch)
  • API/Presentation Layer (Grafana)
Note

Red Hat OpenStack Platform director does not deploy the server-side components for centralized logging. Red Hat does not support the server-side components, including the Elasticsearch database and Grafana.

2.2. Enabling centralized logging with Elasticsearch

To enable centralized logging, you must specify the implementation of the OS::TripleO::Services::Rsyslog composable service.

Note

The Rsyslog service uses only Elasticsearch as a data store for centralized logging.

Prerequisites

  • Elasticsearch is installed on the server side.

Procedure

  • Add the file path of the logging environment file to the overcloud deployment command with any other environment files that are relevant to your environment and deploy, as shown in the following example:

    openstack overcloud deploy \
    <existing_overcloud_environment_files> \
    -e /usr/share/openstack-tripleo-heat-templates/environments/logging-environment-rsyslog.yaml

    Replace <existing_overcloud_environment_files> with the list of environment files that are part of your existing deployment.

2.3. Configuring logging features

To configure logging features, modify the RsyslogElasticsearchSetting parameter in the logging-environment-rsyslog.yaml file.

Procedure

  1. Copy the tripleo-heat-templates/environments/logging-environment-rsyslog.yaml file to your home directory.
  2. Create entries in the RsyslogElasticsearchSetting parameter to suit your environment. The following snippet is an example configuration of the RsyslogElasticsearchSetting parameter:

    parameter_defaults:
        RsyslogElasticsearchSetting:
            uid: "elastic"
            pwd: "yourownpassword"
            skipverifyhost: "on"
            allowunsignedcerts: "on"
            server: "https://log-store-service-telemetry.apps.stfcloudops1.lab.upshift.rdu2.redhat.com"
            serverport: 443

Additional resources

2.3.1. Configurable logging parameters

This table contains descriptions of logging parameters that you use to configure logging features in Red Hat OpenStack Platform (RHOSP). You can find these parameters in the tripleo-heat-templates/deployment/logging/rsyslog-container-puppet.yaml file.

Table 2.1. Configurable logging parameters

ParameterDescription

RsyslogElasticsearchSetting

Configuration for rsyslog-elasticsearch plugin. For more information, see https://www.rsyslog.com/doc/v8-stable/configuration/modules/omelasticsearch.html.

RsyslogElasticsearchTlsCACert

Contains the content of the CA cert for the CA that issued the Elasticsearch server cert.

RsyslogElasticsearchTlsClientCert

Contains the content of the client cert for doing client cert authorization against Elasticsearch.

RsyslogElasticsearchTlsClientKey

Contains the content of the private key corresponding to the cert RsyslogElasticsearchTlsClientCert.

2.4. Overriding the default path for a log file

If you modify the default containers and the modification includes the path to the service log file, you must also modify the default log file path. Every composable service has a <service_name>LoggingSource parameter. For example, for the nova-compute service, the parameter is NovaComputeLoggingSource.

Procedure

  • To override the default path for the nova-compute service, add the path to the NovaComputeLoggingSource parameter in your configuration file:

     NovaComputeLoggingSource:
          tag: openstack.nova.compute
          file: /some/other/path/nova-compute.log
    Note

    For each service, define the tag and file. Other values are derived by default.

    1. You can modify the format for a specific service. This passes directly to the Rsyslog configuration. The default format for the LoggingDefaultFormat parameter is /(?<time>\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}.\d+) (?<pid>\d+) (?<priority>\S+) (?<message>.*)$/ Use the following syntax:

      <service_name>LoggingSource:
          tag: <service_name>.tag
          path: <service_name>.path
          format: <service_name>.format

      The following snippet is an example of a more complex transformation:

       ServiceLoggingSource:
          tag: openstack.Service
          path: /var/log/containers/service/service.log
          format: multiline
          format_firstline: '/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}.\d{3} \d+ \S+ \S+ \[(req-\S+ \S+ \S+ \S+ \S+ \S+|-)\]/'
          format1: '/^(?<Timestamp>\S+ \S+) (?<Pid>\d+) (?<log_level>\S+) (?<python_module>\S+) (\[(req-(?<request_id>\S+) (?<user_id>\S+) (?<tenant_id>\S+) (?<domain_id>\S+) (?<user_domain>\S+) (?<project_domain>\S+)|-)\])? (?<Payload>.*)?$/'

2.5. Modifying the format of a log record

You can modify the format of the start of the log record for a specific service. This passes directly to the Rsyslog configuration.

The default format for the Red Hat OpenStack Platform (RHOSP) log record is ('^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}(.[0-9]+ [0-9]+)? (DEBUG|INFO|WARNING|ERROR) ').

Procedure

  • To add a different regular expression for parsing the start of log records, add startmsg.regex to the configuration:

    NovaComputeLoggingSource:
           tag: openstack.nova.compute
           file: /some/other/path/nova-compute.log
           startmsg.regex: "^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}(.[0-9]+ \\+[0-9]+)? [A-Z]+ \\([a-z]+\\)

2.6. Testing the connection between Rsyslog and Elasticsearch

On the client side, you can verify communication between Rsyslog and Elasticsearch.

Procedure

  • Navigate to the Elasticsearch connection log file, /var/log/rsyslog/omelasticsearch.log in the Rsyslog container or /var/log/containers/rsyslog/omelasticsearch.log on the host. If this log file does not exist or if the log file exists but does not contain logs, there is no connection problem. If the log file is present and contains logs, Rsyslog has not connected successfully.
Note

To test the connection from the server side, view the Elasticsearch logs for connection issues.

2.7. Server-side logging

If you have an Elasticsearch cluster running, you must configure the RsyslogElasticsearchSetting parameter in the logging-environment-rsyslog.yaml file to connect Rsyslog that is running on overcloud nodes. To configure the RsyslogElasticsearchSetting parameter, see https://www.rsyslog.com/doc/v8-stable/configuration/modules/omelasticsearch.html

2.8. Tracebacks

When you encounter an issue and you start troubleshooting, you can use a traceback log to diagnose the issue. In log files, tracebacks usually have several lines of information, all relating to the same issue.

Rsyslog provides a regular expression to define how a log record starts. Each log record usually starts with a timestamp and the first line of the traceback is the only line that contains this information. Rsyslog bundles the indented records with the first line and sends them as one log record.

For that behaviour configuration option startmsg.regex in <Service>LoggingSource is used. The following regular expression is the default value for all <service>LoggingSource parameters in director:

startmsg.regex='^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}(.[0-9]+ [0-9]+)? (DEBUG|INFO|WARNING|ERROR) '

When this default does not match log records of your added or modified LoggingSource, you must change startmsg.regex accordingly.

2.9. Location of log files for OpenStack services

Each OpenStack component has a separate logging directory containing files specific to a running service.

2.9.1. Bare Metal Provisioning (ironic) log files

ServiceService nameLog path

OpenStack Ironic API

openstack-ironic-api.service

/var/log/containers/ironic/ironic-api.log

OpenStack Ironic Conductor

openstack-ironic-conductor.service

/var/log/containers/ironic/ironic-conductor.log

2.9.2. Block Storage (cinder) log files

ServiceService nameLog path

Block Storage API

openstack-cinder-api.service

/var/log/containers/cinder-api.log

Block Storage Backup

openstack-cinder-backup.service

/var/log/containers/cinder/backup.log

Informational messages

The cinder-manage command

/var/log/containers/cinder/cinder-manage.log

Block Storage Scheduler

openstack-cinder-scheduler.service

/var/log/containers/cinder/scheduler.log

Block Storage Volume

openstack-cinder-volume.service

/var/log/containers/cinder/volume.log

2.9.3. Compute (nova) log files

ServiceService nameLog path

OpenStack Compute API service

openstack-nova-api.service

/var/log/containers/nova/nova-api.log

OpenStack Compute certificate server

openstack-nova-cert.service

/var/log/containers/nova/nova-cert.log

OpenStack Compute service

openstack-nova-compute.service

/var/log/containers/nova/nova-compute.log

OpenStack Compute Conductor service

openstack-nova-conductor.service

/var/log/containers/nova/nova-conductor.log

OpenStack Compute VNC console authentication server

openstack-nova-consoleauth.service

/var/log/containers/nova/nova-consoleauth.log

Informational messages

nova-manage command

/var/log/containers/nova/nova-manage.log

OpenStack Compute NoVNC Proxy service

openstack-nova-novncproxy.service

/var/log/containers/nova/nova-novncproxy.log

OpenStack Compute Scheduler service

openstack-nova-scheduler.service

/var/log/containers/nova/nova-scheduler.log

2.9.4. Dashboard (horizon) log files

ServiceService nameLog path

Log of certain user interactions

Dashboard interface

/var/log/containers/horizon/horizon.log

The Apache HTTP server uses several additional log files for the Dashboard web interface, which you can access by using a web browser or command-line client, for example, keystone and nova. The log files in the following table can be helpful in tracking the use of the Dashboard and diagnosing faults:

PurposeLog path

All processed HTTP requests

/var/log/containers/httpd/horizon_access.log

HTTP errors

/var/log/containers/httpd/horizon_error.log

Admin-role API requests

/var/log/containers/httpd/keystone_wsgi_admin_access.log

Admin-role API errors

/var/log/containers/httpd/keystone_wsgi_admin_error.log

Member-role API requests

/var/log/containers/httpd/keystone_wsgi_main_access.log

Member-role API errors

/var/log/containers/httpd/keystone_wsgi_main_error.log

Note

There is also /var/log/containers/httpd/default_error.log, which stores errors reported by other web services that are running on the same host.

2.9.5. Identity Service (keystone) log files

ServiceService nameLog Path

OpenStack Identity Service

openstack-keystone.service

/var/log/containers/keystone/keystone.log

2.9.6. Image Service (glance) log files

ServiceService nameLog path

OpenStack Image Service API server

openstack-glance-api.service

/var/log/containers/glance/api.log

OpenStack Image Service Registry server

openstack-glance-registry.service

/var/log/containers/glance/registry.log

2.9.7. Networking (neutron) log files

ServiceService nameLog path

OpenStack Neutron DHCP Agent

neutron-dhcp-agent.service

/var/log/containers/neutron/dhcp-agent.log

OpenStack Networking Layer 3 Agent

neutron-l3-agent.service

/var/log/containers/neutron/l3-agent.log

Metadata agent service

neutron-metadata-agent.service

/var/log/containers/neutron/metadata-agent.log

Metadata namespace proxy

n/a

/var/log/containers/neutron/neutron-ns-metadata-proxy-UUID.log

Open vSwitch agent

neutron-openvswitch-agent.service

/var/log/containers/neutron/openvswitch-agent.log

OpenStack Networking service

neutron-server.service

/var/log/containers/neutron/server.log

2.9.8. Object Storage (swift) log files

OpenStack Object Storage sends logs to the system logging facility only.

Note

By default, all Object Storage log files go to /var/log/containers/swift/swift.log, using the local0, local1, and local2 syslog facilities.

The log messages of Object Storage are classified into two broad categories: those by REST API services and those by background daemons. The API service messages contain one line per API request, in a manner similar to popular HTTP servers; both the frontend (Proxy) and backend (Account, Container, Object) services post such messages. The daemon messages are less structured and typically contain human-readable information about daemons performing their periodic tasks. However, regardless of which part of Object Storage produces the message, the source identity is always at the beginning of the line.

Here is an example of a proxy message:

Apr 20 15:20:34 rhev-a24c-01 proxy-server: 127.0.0.1 127.0.0.1 20/Apr/2015/19/20/34 GET /v1/AUTH_zaitcev%3Fformat%3Djson%26marker%3Dtestcont HTTP/1.0 200 - python-swiftclient-2.1.0 AUTH_tk737d6... - 2 - txc454fa8ea4844d909820a-0055355182 - 0.0162 - - 1429557634.806570053 1429557634.822791100

Here is an example of ad-hoc messages from background daemons:

Apr 27 17:08:15 rhev-a24c-02 object-auditor: Object audit (ZBF). Since Mon Apr 27 21:08:15 2015: Locally: 1 passed, 0 quarantined, 0 errors files/sec: 4.34 , bytes/sec: 0.00, Total time: 0.23, Auditing time: 0.00, Rate: 0.00
Apr 27 17:08:16 rhev-a24c-02 object-auditor: Object audit (ZBF) "forever" mode completed: 0.56s. Total quarantined: 0, Total errors: 0, Total files/sec: 14.31, Total bytes/sec: 0.00, Auditing time: 0.02, Rate: 0.04
Apr 27 17:08:16 rhev-a24c-02 account-replicator: Beginning replication run
Apr 27 17:08:16 rhev-a24c-02 account-replicator: Replication run OVER
Apr 27 17:08:16 rhev-a24c-02 account-replicator: Attempted to replicate 5 dbs in 0.12589 seconds (39.71876/s)
Apr 27 17:08:16 rhev-a24c-02 account-replicator: Removed 0 dbs
Apr 27 17:08:16 rhev-a24c-02 account-replicator: 10 successes, 0 failures

2.9.9. Orchestration (heat) log files

ServiceService nameLog path

OpenStack Heat API Service

openstack-heat-api.service

/var/log/containers/heat/heat-api.log

OpenStack Heat Engine Service

openstack-heat-engine.service

/var/log/containers/heat/heat-engine.log

Orchestration service events

n/a

/var/log/containers/heat/heat-manage.log

2.9.10. Shared Filesystem Service (manila) log files

ServiceService nameLog path

OpenStack Manila API Server

openstack-manila-api.service

/var/log/containers/manila/api.log

OpenStack Manila Scheduler

openstack-manila-scheduler.service

/var/log/containers/manila/scheduler.log

OpenStack Manila Share Service

openstack-manila-share.service

/var/log/containers/manila/share.log

Note

Some information from the Manila Python library can also be logged in /var/log/containers/manila/manila-manage.log.

2.9.11. Telemetry (ceilometer) log files

ServiceService nameLog path

OpenStack ceilometer notification agent

ceilometer_agent_notification

/var/log/containers/ceilometer/agent-notification.log

OpenStack ceilometer central agent

ceilometer_agent_central

/var/log/containers/ceilometer/central.log

OpenStack ceilometer collection

openstack-ceilometer-collector.service

/var/log/containers/ceilometer/collector.log

OpenStack ceilometer compute agent

ceilometer_agent_compute

/var/log/containers/ceilometer/compute.log

2.9.12. Log files for supporting services

The following services are used by the core OpenStack components and have their own log directories and files.

ServiceService nameLog path

Message broker (RabbitMQ)

rabbitmq-server.service

/var/log/rabbitmq/rabbit@short_hostname.log
/var/log/rabbitmq/rabbit@short_hostname-sasl.log (for Simple Authentication and Security Layer related log messages)

Database server (MariaDB)

mariadb.service

/var/log/mariadb/mariadb.log

Virtual network switch (Open vSwitch)

openvswitch-nonetwork.service

/var/log/openvswitch/ovsdb-server.log
/var/log/openvswitch/ovs-vswitchd.log

2.9.13. aodh (alarming service) log files

ServiceContainer nameLog path

Alarming API

aodh_api

/var/log/containers/httpd/aodh-api/aodh_wsgi_access.log

Alarm evaluator log

aodh_evaluator

/var/log/containers/aodh/aodh-evaluator.log

Alarm listener

aodh_listener

/var/log/containers/aodh/aodh-listener.log

Alarm notification

aodh_notifier

/var/log/containers/aodh/aodh-notifier.log

2.9.14. gnocchi (metric storage) log files

ServiceContainer nameLog path

Gnocchi API

gnocchi_api

/var/log/containers/httpd/gnocchi-api/gnocchi_wsgi_access.log

Gnocchi metricd

gnocchi_metricd

/var/log/containers/gnocchi/gnocchi-metricd.log

Gnocchi statsd

gnocchi_statsd  

/var/log/containers/gnocchi/gnocchi-statsd.log