Service Management - Caching
CAS service definitions that are loaded from service registries are cached with a expire-after-write expiration policy.
Such definition are automatically expired and removed from the cache, unless forcefully removed with an explicit reload operation.
In particular, you want to make sure the cache expiration policy and period does not conflict with reload operations and schedules.
For example, misconfiguration can lead to scenarios where the cache might be running empty while the scheduler is running a
few minutes/seconds late. With an empty cache, authentication requests from applications might not be immediately authorized
until the scheduled loader has had a chance to re-populate and reconstruct the cache. CAS logs a warning at startup
when the cache expires service definitions before the scheduler reloads them; the cache duration should always be
longer than the scheduler’s repeat interval.
The following settings and properties are available from the CAS configuration catalog:
cas.service-registry.cache.cache-sizeThis cache size specifies the maximum number of entries the cache may contain.
10000This cache size specifies the maximum number of entries the cache may contain. Note that the cache may evict an entry before this limit is exceeded or temporarily exceed the threshold while evicting. As the cache size grows close to the maximum, the cache evicts entries that are less likely to be used again. For example, the cache may evict an entry because it hasn't been used recently or very often. Note: to disable the cache, you may choose a cache size of 0.
cas.service-registry.cache.durationCache duration specifies the fixed duration for an entry to be automatically removed from the cache after its creation.
PT15MCache duration specifies the fixed duration for an entry to be automatically removed from the cache after its creation.
cas.service-registry.cache.initial-capacityThis cache capacity sets the minimum total size for the internal data structures.
1000This cache capacity sets the minimum total size for the internal data structures. Providing a large enough estimate at construction time avoids the need for expensive resizing operations later, but setting this value unnecessarily high wastes memory.
Required settings may be needed to activate or affect the feature; review them even when they have a default. Optional settings only need to be set to change a default or to turn on the behavior they control. Third party settings belong to libraries such as Spring Boot that CAS builds on; their own documentation may have more detail.
Notes on configuration
Configuration Metadata
The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.
Be Selective
This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.
YAGNI
Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.
Naming Convention
Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all
forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where
this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those
that might be presented to the system via an external library or framework such as Spring Boot, etc.
Note
When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value.
The only possible exception to this rule is when naming actuator endpoints; The name of the
actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.
Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided
to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with
the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition
or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the
way you intend.
Validation
Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.
Indexed Settings
CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be
incremented by the adopter to allow for distinct multiple configuration blocks.
Unmatched Services
When the background scheduler is enabled and the cache size is greater than zero, CAS matches the requested application against cached service definitions only. A request for an application that matches no cached definition is rejected without reading the service registry, so requests for unknown applications cannot force a read of the whole registry. A definition added to the registry outside this CAS server, such as by another CAS node or directly in the database or repository behind the registry, is recognized after the next scheduled reload.
- Definitions saved or deleted through CAS update the cache immediately, and so do files added, changed or removed in a JSON or YAML registry directory while its watcher is enabled.
- The service registry is still consulted for unmatched requests when the scheduler is disabled or the cache size is
0. - Lookups by numeric identifier or by name continue to consult the service registry when the cache has no match.
Service Management - Reloading
CAS can be configured to load service definitions from connected sources and service registries on a schedule. Service definitions are loaded as background-running job, and the operation forces CAS to flush and invalidate cached version of service definitions and start anew.
UtilityThe background scheduler reloads application definitions from a source regardless of the service registry type. It disregards the currently-loaded list of applications and fetches a new copy from the source, whatever that may be.
The following settings and properties are available from the CAS configuration catalog:
cas.service-registry.schedule.cron-expressionA cron-like expression, extending the usual UN*X definition to include triggers on the second, minute, hour, day of month, month, and day of week.
A cron-like expression, extending the usual UN*X definition to include triggers on the second, minute, hour, day of month, month, and day of week. For example, 0 * * * * MON-FRI means once per minute on weekdays (at the top of the minute - the 0th second) or 0 0 0 * * * means every day at midnight. * Note that when cron expressions are defined, the start delay and repeat interval settings are must be removed and set to blank.
cas.service-registry.schedule.cron-time-zoneA time zone for which the cron expression will be resolved.
A time zone for which the cron expression will be resolved. By default, this attribute is empty (i.e. the scheduler's time zone will be used).
cas.service-registry.schedule.enabledWhether scheduler should be enabled to schedule the job to run.
trueWhether scheduler should be enabled to schedule the job to run.
cas.service-registry.schedule.enabled-on-hostOverrides SchedulingProperties#enabled property value of true if this property does not match hostname of CAS server.
.*Overrides SchedulingProperties#enabled property value of true if this property does not match hostname of CAS server. This can be useful if deploying CAS with an image in a statefulset where all names are predictable but where having different configurations for different servers is hard. The value can be an exact hostname or a regular expression that will be used to match the hostname.
cas.service-registry.schedule.repeat-intervalString representation of a repeat interval of re-loading data for a data store implementation.
PT2MString representation of a repeat interval of re-loading data for a data store implementation. This is the timeout between consecutive job’s executions.
cas.service-registry.schedule.start-delayString representation of a start delay of loading data for a data store implementation.
PT15SString representation of a start delay of loading data for a data store implementation. This is the delay between scheduler startup and first job’s execution
Required settings may be needed to activate or affect the feature; review them even when they have a default. Optional settings only need to be set to change a default or to turn on the behavior they control. Third party settings belong to libraries such as Spring Boot that CAS builds on; their own documentation may have more detail.
Notes on configuration
Configuration Metadata
The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.
Be Selective
This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.
YAGNI
Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.
Naming Convention
Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all
forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where
this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those
that might be presented to the system via an external library or framework such as Spring Boot, etc.
Note
When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value.
The only possible exception to this rule is when naming actuator endpoints; The name of the
actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.
Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided
to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with
the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition
or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the
way you intend.
Validation
Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.
Indexed Settings
CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be
incremented by the adopter to allow for distinct multiple configuration blocks.