GOCDB/Release4/Development/v5

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v5 Release Summary

v5 Benefits of changing the DB model (dropping PROM for doctrine)

  • Write code once, deploy to Oracle, MySQL, Postgres, SQLite.
  • Much simpler than the GOCDB/PROM model (see query comparison below)]
  • Easier for other projects to extend / modify
  • Easier for new developers to learn
  • Better performance
  • Doctrine is de-facto object-relational-mapping library (ORM) for PHP.
    • Reduced risk of fail over performance issues
PROM SQL
Doctrine SQL

Drawbacks

  • Data will be deleted rather than marked as 'off'. We therefore require an audit table to record who/when performed data deletions/updates (this is on the requirements roadmap ).
  • Loose some flexiblity as the DB will manage the relationships (FKs) between entities rather than the application (but in turn we gain performance/simplicity/db-agnostic).
  • Changes to some PI methods (paging and carrying over v4 PKs)
  • Changes to Portal URLs and object IDs (below)

Changes

The move to Doctrine will introduce some important changes. These are outlined below.

Portal URLs

In PROM, each "entity" (site, service endpoint, downtime) was assigned an ID from a global pool. There is only one object 123, the GRIDOPS-GOCDB site. The following URL is used to access an entity regardless of type:

https://goc.egi.eu/portal/index.php?Page_Type=View_Object&object_id=123&grid_id=0

In v5 using Doctrine, each entity receives an ID unique only to that entity type. There is a site with ID 123, a service endpoint with ID 123 and a downtime with ID 123. The new URL will reflect the entity type:

https://goc.egi.eu/portal/index.php?Page_Type=Site&id=123

https://goc.egi.eu/portal/index.php?Page_Type=Service_Endpoint&id=123

https://goc.egi.eu/portal/index.php?Page_Type=Downtime&id=123

(...and so on for each GOCDB entity type)

GOCDB URLs.png


PI XML Output Values

In the GOCDB v4 PI there are a number of PROM specific XML values that will change when we move to Doctrine: PRIMARY_KEY, ID and GOCDB_PORTAL_URL. These are highlighted in RED below:

Get Site Fields.png

  • ID fields will NOT be consistent between v4 and v5 (each new object will get a new Doctrine ID value).
  • The GOCDB_PORTAL_URL will therefore NOT be consistent between v4 and v5.
  • The v4 PRIMARY_KEY value will be carried over only for Sites and Downtimes, see below:



Update Aug 2013 - Preserving v4 <PRIMARY_KEY> element values

  • v4 <PRIMARY_KEY> element values are carried over for Sites and Downtimes to maintain backward compatiblity (get_site, get_site_list, get_downtime)
  • No preservation of v4 <PRIMARY_KEY> element values for:
    • get_service_endpoint
    • get_ngi
    • get_service_group
    • Please check!

PI get_downtime method paging

  • The ‘get_downtime’ PI method supports a new ‘&page’ parameter to limit the number of returned downtimes to a manageable limit (1000 in each page).
  • The page parameter is optional. If not specified, a query returns all matching results.
  • Paging should be used with care – since pending downtimes can be deleted, it is not guaranteed that all downtimes will be returned in sequence if downtimes are actively deleted in the time taken to issue a sequence of paged-queries.
  • If you invoke ‘get_downtime’ with no query parameters to narrow your search then the query can potentially time-out because too many downtimes are requested in one hit. In this scenario, consider narrowing your query with additional query parameters before using paging.
  • The 'get_downtime' method can be re-issued by the client and each time the page parameter should be incremented by one until an empty <results/> element is returned indicating no more results, e.g.

PI get_downtime method 'all_lastmonth'

  • ‘&all_lastmonth’ can be used to return all downtimes that have started or will start within 1month+1day from current date (inc. current and future DTs).
  • Results are not paged - *all* DTs returned for this window. ‘&page’ parameter can be excluded if specifying ‘all_lastmonth’ e.g.
  • WARNING: The number of results should normally fall within the page limit, but since paging is turned off, this query could potentially be expensive/problematic if there are many more DTs than the page limit. Without paging, this query can theoretically fail!


PI Scope Extensions

  • Scoping is being extended in v5 so that resources from multiple projects/infrastructures can be hosted in a single gocdb instance - see GOCDB/Release4/Development/conditionalCertificationStatusRules
  • Important: the scope extensions are backward compatible and will not break clients' existing PI queries.
  • The optional PI ‘&scope’ parameter will allow a comma-sep list of values rather than a single ‘EGI’ or ‘Local’ value.
  • An empty value can be used to ignore scope filtering: ‘&scope=’
  • If ‘&scope’ is not specified, ‘EGI’ is matched by default to preserve v4 behaviour.
  • New ‘&scope_match’ parameter for methods supporting &scope:
    • ‘&scope_match=any’ matches entities that define any of the specified scopes
    • ‘&scope_match=all’ matches entities that define all of the specified scopes

Examples:

  • Return sites that define either the EGI or PROJX scope tags: 

https://gocdb-test.esc.rl.ac.uk/v5_pi/public/?method=get_site&scope=EGI,PROJX&scope_match=any

  • Return sites that define both the EGI and PROJX scope tags:

https://gocdb-test.esc.rl.ac.uk/v5_pi/public/?method=get_site&scope=EGI,PROJX&scope_match=all

  • Return sites that define the default configured scope tag (‘EGI’) in our case (scope tag not specified):

https://gocdb-test.esc.rl.ac.uk/v5_pi/public/?method=get_site

  • Return sites irrespective of their scope tags (empty ‘scope=’):

https://gocdb-test.esc.rl.ac.uk/v5_pi/public/?method=get_site&scope=

  • Return all DTs for Services that define both PROJX+EGI scope (scope references the Service scope):

https://gocdb-test.esc.rl.ac.uk/v5_pi/public/?method=get_downtime&scope=PROJX,EGI&scope_match=all

Request for Comments

If these changes affect a system that reads from the GOCDB-PI or links to the web portal please let us know.