Follow the PBS Pro Design Document Guidelines.
Link to discussion on Developer Forum: <http://community.pbspro.org/t/design-for-refactoring-pbs-database-code/2009>
Link to issue: <issue link if available>
Link to pull request: <PR link if available>
For easy maintainability, current database-related code within the PBS server needs to be refactored into a separate pluggable dynamic library. And this design page discusses the APIs using which PBS server can talk to Libdb, the database dynamic library using which PBS can talk to the database. Another motivation behind this refactoring is the added advantage of moving to any database without having to do major code changes within PBS itself.
1.1. Files: List of files PBS will need to have database support.
PBS_EXEC/lib/libdb.so
Description: This dynamic library will have the functionality for the PBS server to access the database.
...
PBS_EXEC/libexec/pbs_db_env.sh
Description: This script will initialize the environment with information related to the database installation path.
...
Code Block |
---|
struct pbs_db_obj_info { int pbs_db_obj_type; /* identifies the contained object type */ union { pbs_db_job_info_t *pbs_db_job; /* map database job structure to C */ pbs_db_jobscr_info_t *pbs_db_jobscr; /* map database job script to C */ pbs_db_resv_info_t *pbs_db_resv; /* map database resv structure to C */ pbs_db_svr_info_t *pbs_db_svr; /* map database server structure to C */ pbs_db_que_info_t *pbs_db_que; /* map database queue structure to C */ pbs_db_node_info_t *pbs_db_node; /* map database node structure to C */ pbs_db_sched_info_t *pbs_db_sched; /* map database scheduler structure to C */ pbs_db_mominfo_time_t *pbs_db_mominfo_tm; /* map database mominfo_time structure to C */ } pbs_db_un; }; typedef struct pbs_db_obj_info pbs_db_obj_info_t; /* Structure used to map database job structure to C */ struct pbs_db_job_info { char ji_jobid[PBS_MAXSVRJOBID + 1]; /* job identifier */ INTEGER ji_state; /* INTEGERernalInternal copy of state */ INTEGER ji_substate; /* job sub-state */ INTEGER ji_svrflags; /* server flags */ INTEGER ji_numattr; /* not used */ INTEGER ji_ordering; /* special scheduling ordering */ INTEGER ji_priority; /* INTEGERernal priority */ BIGINT ji_stime; /* time job started execution */ BIGINT ji_endtBdry; /* estimate upper bound on end time */ char ji_queue[PBS_MAXQUEUENAME + 1]; /* name of current queue */ char ji_destin[PBS_MAXROUTEDEST + 1]; /* dest from qmove/route */ INTEGER ji_un_type; /* job's queue type */ INTEGER ji_momaddr; /* host addr of Server */ INTEGER ji_momport; /* port # */ INTEGER ji_exitstat; /* job exit status from MOM */ BIGINT ji_quetime; /* time entered queue */ BIGINT ji_rteretry; /* route retry time */ INTEGER ji_fromsock; /* socket job coming over */ BIGINT ji_fromaddr; /* host job coming from */ char ji_4jid[8]; /* extended job save data */ char ji_4ash[8]; /* extended job save data */ INTEGER ji_credtype; /* credential type */ INTEGERBIGINT ji_qrank; /* sort key for db query */ char ji_savetm[DB_TIMESTAMP_LEN + 1]; /* job save time */ char ji_creattm[DB_TIMESTAMP_LEN + 1]; /* job create time */ pbs_db_attr_list_t db_attr_list; /* list of attributes for database */ pbs_db_attr_list_t cache_attr_list; /* list of attributes to save in cache */ }; typedef struct pbs_db_job_info pbs_db_job_info_t; /* Structure used to map database resv structure to C */ struct pbs_db_resv_info { char ri_resvid[PBS_MAXSVRJOBID + 1]; /* reservation identifier */ char ri_queue[PBS_MAXQUEUENAME + 1]; /* queue used by reservation */ INTEGER ri_state; /* internal copy of state */ INTEGER ri_substate; /* substate of resv state */ INTEGER ri_type; /* "reservation" or "reservation job"*/ BIGINT ri_pbs_db_attr_list_t db_attr_list; /* list of attributes for database */ }; typedef struct pbs_db_job_info pbs_db_job_info_t; /* Structure used to map database resv structure to C */ struct pbs_db_resv_info { char ri_resvid[PBS_MAXSVRJOBID + 1]; /* reservation identifier */ char ri_queue[PBS_MAXQUEUENAME + 1]; /* queue used by reservation */ INTEGER ri_state; /* internal copy of state */ INTEGER ri_substate; /* substate of resv state */ BIGINT ri_stime; /* left window boundry */ BIGINT ri_etime; /* right window boundry */ BIGINT ri_duration; /* reservation duration */ INTEGER ri_tactive; /* time reservation became active */ INTEGER ri_svrflags; /* server flags */ INTEGER ri_numattr; /* not used */ INTEGER ri_resvTag; /* not used */ INTEGER ri_un_type; /* not used */ INTEGER ri_fromsock; /* resv from sock */ BIGINT ri_fromaddr; /* resv from sock addr */ char ri_creattm[DB_TIMESTAMP_LEN + 1]; /* resv create time on db */ char ri_savetm[DB_TIMESTAMP_LEN + 1]; /* resv save time on db */ pbs_db_attr_list_t cache_attr_list; /* list of attributes */ pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_resv_info pbs_db_resv_info_t; /* Structure used to map database server structure to C */ struct pbs_db_svr_info { BIGINT sv_jobidnumber; pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_resvsvr_info pbs_db_resvsvr_info_t; /* Structure used to map database serverscheduler structure to C */ struct pbs_db_svrsched_info { char sv_creattm[DB_TIMESTAMP_LEN + sched_name[PBS_MAXSCHEDNAME+1]; /* time of server db create */ char sv_savetm[DB_TIMESTAMP_LEN + 1]; /* time of server db update */ pbs_db_attr_list_t cache_attr_list; /* list of attributes */ pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_svr_info pbs_db_svr_info_t; /* Structure used to map database scheduler structure to C */ struct pbs_db_sched_info { char sched_name[PBS_MAXSCHEDNAME+1]; /* sched name */ char sched_creattm[DB_TIMESTAMP_LEN + 1]; /* sched create time on db */ char sched_savetm[DB_TIMESTAMP_LEN + 1]; /* sched save time on db */ pbs_db_attr_list_t cache_attr_list; /* list of attributes/* sched name */ pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_sched_info pbs_db_sched_info_t; /* Structure used to map database queue structure to C */ struct pbs_db_que_info { char qu_name[PBS_MAXQUEUENAME +1]; /* queue name */ INTEGER qu_type; /* queue type: exec, route */ charstruct qupbs_creattm[DBdb_TIMESTAMPque_LENinfo +{ 1]; /*char time queue created */ char qu_savetmname[DBPBS_TIMESTAMP_LENMAXQUEUENAME + 1]; /* time queue last modifiedname */ pbs_db_attr_list_t cache_attr_list;INTEGER qu_type; /* queue listtype: ofexec, attributesroute */ pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_que_info pbs_db_que_info_t; /* Structure used to map database node structure to C */ struct pbs_db_node_info { char nd_name[PBS_MAXSERVERNAME+1]; /* vnode's name */ INTEGER nd_index; /* globalStructure nodeused indexto */map BIGINT mom_modtime; /* database node configstructure updateto timeC */ struct pbs_db_node_info { char nd_hostnamename[PBS_MAXSERVERNAME+1]; /* node hostname */ INTEGER nd_state; /* state of nodevnode's name */ INTEGER nd_ntypeindex; /* global node typeindex */ char nd_pque[PBS_MAXSERVERNAME+1];BIGINT mom_modtime; /* queuenode toconfig whichupdate node belongstime */ char nd_creattmhostname[DB_TIMESTAMP_LEN + PBS_MAXSERVERNAME+1]; /* node create timehostname */ charINTEGER nd_savetm[DB_TIMESTAMP_LEN + 1]state; /* state of node */ INTEGER nd_ntype; /* node savetype time */ char pbsnd_db_attr_list_t cache_attr_list; /* list of attributespque[PBS_MAXSERVERNAME+1]; /* queue to which it belongs */ pbs_db_attr_list_t db_attr_list; /* list of attributes */ }; typedef struct pbs_db_node_info pbs_db_node_info_t; /* Structure used to map database mominfo_time structure to C */ struct pbs_db_mominfo_time { BIGINT mit_time; /* time of the host to vnode map */ INTEGER mit_gen; /* generation of the host to vnode map */ }; typedef struct pbs_db_mominfo_time pbs_db_mominfo_time_t; /* Structure used to map database job script to C */ struct pbs_db_jobscr_info { char ji_jobid[PBS_MAXSVRJOBID + 1]; /* job identifier */ TEXT script; /* job script */ }; typedef struct pbs_db_jobscr_info pbs_db_jobscr_info_t; |
...
Code Block |
---|
struct pbs_db_attr_list { int attr_count; /* attribute count */ pbs_list_head attrs; /* ptr to attr_info structure */ }; typedef struct pbs_db_attr_list pbs_db_attr_list_t; |
1.2. APIs from libdb.so
1.2.1. PBS Objects: Libdb APIs can work with below mentioned PBS objects.
PBS_DB_JOB: To save and update PBS job objects
...
PBS_DB_MOMINFO_TIME: To save/update PBS mominfo_time
1.2.2. pbs_db_connect
Description: Setup a persistent database connection for further use by APIs which will work on PBS objects. On success return the connection information.
...
!0: On connection failure.
1.2.3. pbs_db_disconnect
Description: Disconnect the PBS server from a database connection.
...
0 - for successful database disconnect.
-1 - for failure
1.2.4. pbs_db_save_obj
Description: PBS can use this API to save any of the PBS Objects listed above to the database. Save operation can be an insert or update.
...
1 - Execution succeeded but the statement did not affect any rows.
1.2.5. pbs_db_delete_obj
Description: This API lets PBS delete PBS objects PBS_DB_JOB, PBS_DB_RESV, PBS_DB_NODE, PBS_DB_QUE and PBS_DB_SCHED from the database.
...
1 - Success but no rows deleted
1.2.6. pbs_db_load_obj
Description: This API lets PBS load objects data from the database. This API can work with any of the PBS objects.
Signature:
...
0 - Success
1 - Success but no rows loaded
1.2.7. pbs_db_search
Description: This API can be used to find/search PBS objects PBS_DB_JOB, PBS_DB_RESV, PBS_DB_NODE, PBS_DB_QUE and PBS_DB_SCHED in the database. This API takes a pointer to the callback function as an argument that will work on the records returned from the database based on the query specified by the PBS.
...
Returns: Error code
-1 - Failure
0 0> - Success
1 0 - Success but no rows found
1.2.8. pbs_db_del_attr_obj
Description: This API can be used to delete attributes of a PBS object.
Signature:
int pbs_db_deldelete_attr_obj(void *conn_db_handle, void *obj_id, char *sv_time*conn, pbs_db_attrobj_listinfo_t *cache_attr_listobj, void *obj_id, pbs_db_attr_list_t *db_attr_list)
Parameters:
conn_db_handle[in]: Connection handler to the database which was created by pbs_db_connect.
obj_id[in]: Object id for the delete attributes actionInformation of the object to be found.
svobj_timeid[in]: Save time stamp Object id for the delete operation.cache_attr_list[in]: List of attributes to be deleted from cacheattributes action.
attr_list[in]: List of attributes to be deleted from dbDB.
Returns: Error code
0 - Success
Non zero - On Failure
1.2.9. pbs_start_db
Description: This API can be used to start the database instance.
...
0 - Success
Non zero - On Failure
1.2.10. pbs_stop_db
Description: This API can be used to stop the database instance.
...
0 - Success
Non zero - On Failure
1.2.11. pbs_status_db
Description: This API can be used to check if the database instance is running.
...
0 - Database is running on the localhost.
-1 - On Failure
1.2.12. pbs_db_password
Description: This API can be used to change the database user and password for the database instance.
...
0 - Success
Non zero - On Failure
1.2.12.
...
pbs_db_get_errmsg
Description: This API can be used to get the error messages from the database library. When any of the above-listed APIs fail, this API can be used to get the error message from libdb.
Signature:
void getpbs_db_get_errmsg(int failcode, char **errmsg)
...