On Semantic Detection of Cloud API (Anti)Patterns

Cloud (Anti)Patterns: OCCI Perspective

OCCI (anti)patterns represent the good and bad practices in the OCCI RESTful Protocol that we have identified by performing a rigorous and deep analysis on all principles defined under this specification. We distinguished three categories of (anti)patterns: Management Related (Anti)Patterns, Cloud Structure Related (Anti)Patterns, and OCCI REST Related (Anti)Patterns.

Management related (anti)patterns

Query interface support vs Missing query interface
Compliant Create vs. Non-Compliant Create
Compliant Trigger Action vs. Non-Compliant Trigger Action
Compliant Update vs. Non-Compliant Update
Compliant Delete vs. Non-Compliant Delete
Compliant Retrieve vs. Non-Compliant Retrive

Cloud Structure related (anti)patterns

Compliant Link between Resources vs.Non-Compliant Link between Resources
Compliant Association of resource(s) with Mixin vs. Non-compliant Association of resource(s) With Mixin
Compliant Dissociation of resource(s) From Mixin vs. Non-compliant dissociation of resource(s) From Mixin

OCCI REST related (anti)patterns

Compliant URL vs. Non-Compliant URL
Compliant Request Header vs. Non-Compliant Request Header
Compliant Response Header vs. Non- Compliant Response Header

Cloud (Anti)Patterns: REST Perspective

REST (anti)patterns represent the good and bad practices in the REST APIs regardless of any cloud standard. We distinguished five categories of (anti)patterns: URI (anti)patterns, HTTP methods (anti)patterns, Error Handling (anti)patterns, HTTP Header (anti)patterns, Hypermedia (anti)patterns.

URI (anti)patterns

Verbless URIs vs. CRUDy URIs
Tidy URIs vs. Amorphous URIs
Compliant Update vs. Non-Compliant Update
Singularized nodes vs. pluralized nodes

HTTP methods (anti)patterns

Correct use of POST, GET, PUT, DELETE, HEAD vs. Tunneling every things through GET and POST

Error handling (Anti)Patterns

Supporting Status Code vs. Ignoring Status Code

HTTP Header (Anti)Patterns

Supporting Caching vs. Ignoring Caching
Supporting MIME Types vs. Ignoring MIME Types

Hypermedia (Anti)Patterns

Supporting Hypermedia vs. Forgetting Hypermedia

Examples of semantic detection rules

SWRL Rules for Query interface support pattern and Missing query interface anti-pattern

(Anti)patterns	SWRL rules
Query interface support pattern	Rest:API(?ap)^ Rest:ComposedOf(?ap,?operation)^ Rest:hasURL(?operation, ?url)^ Rest:value(?url, ?urlval)^ swrlb:matches(?urlval,“\-\”)^ Rest:hasHttpMethod(? operation, ?httpmethod)^ Rest:verb(?httpmethod, ?verb)^ detection:matchesOne(?verb, “POST”, “PUT”, “GET”, “DELETE”)->Rest:hasPattern(?ap, Ptt:Query_interface_support)
Missing query interface anti-pattern	Rest:API(?ap)^ Rest:ComposedOf(?ap, ?operation)^ Rest:hasURL(?operation,?url)^Rest:value(?url, “\-\” )^ sqwrl:makeSet(?s1, ?url)^sqwrl:isEmpty(?s1) ->Rest:hasAntiPattern(?ap, Att:Missing_query_interface)

SWRL rules for Compliant Trigger Action pattern and Non-Compliant Trigger Action anti-pattern

(Anti)patterns	SWRL rules
Compliant Trigger Action	Rest:Operation(?op) ^ Rest:type(?op, "Trigger Action") ^ Rest:hasHttpMethod(?op, ?httpmd) ^ Rest:verb(?httpmd, ?verb) ^ swrlb:matches(?verb, "POST") ^ Rest:hasRequest(?op, ?req) ^ Rest:hasRq-Body(?req, ?reqbody) ^ Rest:hasParameterDefinition(?reqbody, ?pradef) ^ Occi:Action(?action) ^ Rest:isComposedOf(?pradef, ?action) ^ Occi:term(?action, ?term) ^ Occi:scheme(?action, ?scheme) ^ Occi:class(?action, "action") ^ Rest:hasURL(?op, ?url) ^ Rest:value(?url, ?value) ^ swrlb:contains(?value, "action=") ^ swrlb:endsWith(?value, ?term) -> Rest:hasPattern(?op, Ptt:Compliant_Trigger_Action)
Non-Compliant Trigger Action anti-pattern	Rest:Operation(?op) ^ Rest:type(?op, "Trigger Action") ^ Rest:hasHttpMethod(?op, ?httpmd) ^ Rest:verb(?httpmd, ?verb) ^ swrlb:notEqual(?verb, "POST") Rest:hasAntipattern(?op, Att:Non-CompliantTriggerAction) - Rest:Operation(?op)^Rest:type(?op, "Trigger Action")^Rest:hasURL(?op, ?url) ^ Rest:value(?url, ?value) ^ detection:notcontains(?value, "action=") -> Rest:hasAntiPattern(?op, Ptt:Non-Compliant_Trigger_Action)

(Anti)patterns

SWRL rules

Compliant Trigger Action

Rest:Operation(?op) ^ Rest:type(?op, "Trigger Action") ^ Rest:hasHttpMethod(?op, ?httpmd) ^ Rest:verb(?httpmd, ?verb) ^ swrlb:matches(?verb, "POST") ^ Rest:hasRequest(?op, ?req) ^ Rest:hasRq-Body(?req, ?reqbody) ^ Rest:hasParameterDefinition(?reqbody, ?pradef) ^ Occi:Action(?action) ^ Rest:isComposedOf(?pradef, ?action) ^ Occi:term(?action, ?term) ^ Occi:scheme(?action, ?scheme) ^ Occi:class(?action, "action") ^ Rest:hasURL(?op, ?url) ^ Rest:value(?url, ?value) ^ swrlb:contains(?value, "action=") ^ swrlb:endsWith(?value, ?term) -> Rest:hasPattern(?op, Ptt:Compliant_Trigger_Action)

Non-Compliant Trigger Action anti-pattern

Rest:Operation(?op) ^ Rest:type(?op, "Trigger Action") ^ Rest:hasHttpMethod(?op, ?httpmd) ^ Rest:verb(?httpmd, ?verb) ^ swrlb:notEqual(?verb, "POST") Rest:hasAntipattern(?op, Att:Non-CompliantTriggerAction)
- Rest:Operation(?op)^Rest:type(?op, "Trigger Action")^Rest:hasURL(?op, ?url) ^ Rest:value(?url, ?value) ^ detection:notcontains(?value, "action=") -> Rest:hasAntiPattern(?op, Ptt:Non-Compliant_Trigger_Action)

SWRL rules for Verbless URIs pattern and CRUDy URIs anti-pattern

(Anti)patterns	SWRL rules
Verbless URIs pattern	Rest:Operation(?operation)^ Rest:hasHttpMethod(? operation, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^detection:matchesOne(?verb, "POST", " PUT", "GET", "DELETE") ^ Rest:hasURL(?operation, ?url)^ Rest:value(?url,?urlval)^ detection: contain(?return,?urlval, "create", "update", " read", "delete") ^ swrlb:matches(?return, "False ")->Rest:hasPattern(?operation, Ptt: Verbless_URIs)
CRUDy URIs anti-pattern	- Rest:Operation(?operation) ^ Rest:hasHttpMethod(? operation, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^ detection:matchesOne (?verb, "create", "update", "read", "delete")^Rest: hasAntipattern (?operation, Att:CRUDy_URIs) -Rest:Operation(?operation) ^ Rest:hasURL(? operation, ?url) ^ Rest:value(?url,?urlval) ^ detection:contain(?return,?urlval, "create", " update", "read", "delete") ^ swrlb:matches(? return, "True")->Rest:hasAntipattern (?operation, Att:CRUDy_URIs)

(Anti)patterns

SWRL rules

Verbless URIs pattern

Rest:Operation(?operation)^ Rest:hasHttpMethod(? operation, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^detection:matchesOne(?verb, "POST", " PUT", "GET", "DELETE") ^ Rest:hasURL(?operation, ?url)^ Rest:value(?url,?urlval)^ detection: contain(?return,?urlval, "create", "update", " read", "delete") ^ swrlb:matches(?return, "False ")->Rest:hasPattern(?operation, Ptt: Verbless_URIs)

CRUDy URIs anti-pattern

- Rest:Operation(?operation) ^ Rest:hasHttpMethod(? operation, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^ detection:matchesOne (?verb, "create", "update", "read", "delete")^Rest: hasAntipattern (?operation, Att:CRUDy_URIs)
-Rest:Operation(?operation) ^ Rest:hasURL(? operation, ?url) ^ Rest:value(?url,?urlval) ^ detection:contain(?return,?urlval, "create", " update", "read", "delete") ^ swrlb:matches(? return, "True")->Rest:hasAntipattern (?operation, Att:CRUDy_URIs)

SWRL rules for Tunneling every things through GET and POST anti-patterns

(Anti)patterns	SWRL rules
Tunneling every things through GET anti-pattern	Rest:Operation(?op) ^ Rest:hasHttpMethod(?op, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^ swrlb:matches(?verb, "GET") ^ Rest:URL(?url) ^ Rest:value(?url, ?urlval) ^ detection:contain(?return, ?urlval, "delete", "update", "head", "put") ^ swrlb:matches(?return, "True")-> Rest:hasAntipattern(?url, Att:Tunnelling_every_things_through_GET)
Tunneling every things through POST anti-pattern	- Rest:Operation(?op) ^ Rest:hasHttpMethod(?op, ?httpmethod) ^ Rest:verb(?httpmethod, ?verb) ^ swrlb:matches(?verb, "POST") ^ Rest:URL(?url) ^ Rest:value(?url, ?urlval) ^ detection:contain(?return, ?urlval, "delete", "update", "head", "put") ^ swrlb:matches(?return, "True")-> Rest:hasAntipattern(?url, Att:Tunnelling_every_things_through_POST)

SWRL rules for Ignoring Status Code pattern and Supporting Status Code anti-pattern

(Anti)patterns	SWRL rules
Supporting Status Code pattern	Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ detection:matchelist(?value, "200 (OK), 201 (Created), 201 (Created), 202 (Accepted), 204 (No Content), 204 (No Content), 304 (Not Modified), 400 (Bad Request)") -> Rest:hasPattern(?op, Ptt:Supporting_Status_Code)
Ignoring Status Code anti-pattern	- Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ detection:Notmatchelist(?value, "200 (OK), 201 (Created), 201 (Created), 202 (Accepted), 204 (No Content), 204 (No Content), 304 (Not Modified), 400 (Bad Request)") -> Rest:hasPattern(?op, Att:Ignoring_Status_Code) -Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ swrlb:matches(?value, " ") -> Rest:hasPattern(?op, Att:Ignoring_Status_Code)

(Anti)patterns

SWRL rules

Supporting Status Code pattern

Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ detection:matchelist(?value, "200 (OK), 201 (Created), 201 (Created), 202 (Accepted), 204 (No Content), 204 (No Content), 304 (Not Modified), 400 (Bad Request)") -> Rest:hasPattern(?op, Ptt:Supporting_Status_Code)

Ignoring Status Code anti-pattern

- Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ detection:Notmatchelist(?value, "200 (OK), 201 (Created), 201 (Created), 202 (Accepted), 204 (No Content), 204 (No Content), 304 (Not Modified), 400 (Bad Request)") -> Rest:hasPattern(?op, Att:Ignoring_Status_Code)
-Rest:Operation(?op) ^ Rest:hasCode(?op, ?codestatus) ^ Rest:value(?codestatus, ?value) ^ swrlb:matches(?value, " ") -> Rest:hasPattern(?op, Att:Ignoring_Status_Code)

Contact

Hayet Brabra
Telecom SudParis
Computer Science Departement
email: hayet.brabra (-at-) telecom-sudparis.eu