| | 1 | = Backend program logic = |
| | 2 | |
| | 3 | |
| | 4 | === Work generator === |
| | 5 | |
| | 6 | |
| | 7 | |
| | 8 | {{{ |
| | 9 | for each wu created |
| | 10 | wu.transition_time = now |
| | 11 | }}} |
| | 12 | |
| | 13 | === scheduler === |
| | 14 | |
| | 15 | {{{ |
| | 16 | when send a result |
| | 17 | result.report_deadline = now + wu.delay_bound |
| | 18 | wu.transition_time = min(wu.transition_time, result.report_deadline) |
| | 19 | when receive a result |
| | 20 | if client error |
| | 21 | result.outcome = client_error |
| | 22 | result.validate_state = INVALID |
| | 23 | else |
| | 24 | result.outcome = success |
| | 25 | result.server_state = OVER |
| | 26 | wu.transition_time = now |
| | 27 | when a result falls off the bottom of infeasible queue |
| | 28 | result.server_state = OVER |
| | 29 | result.outcome = COULDNT_SEND |
| | 30 | wu.transition_time = now |
| | 31 | }}} |
| | 32 | |
| | 33 | === Transitioner === |
| | 34 | |
| | 35 | |
| | 36 | |
| | 37 | {{{ |
| | 38 | // gets run when either |
| | 39 | // - a result becomes done (via timeout or client reply) |
| | 40 | // - the WU error mask is set (e.g. by validator) |
| | 41 | // - assimilation is finished |
| | 42 | for each WU with now > transition_time: |
| | 43 | |
| | 44 | // check for timed-out results |
| | 45 | for each result of WU |
| | 46 | if result.server_state = in_progress and now > result.report_deadline |
| | 47 | result.server_state = OVER |
| | 48 | result.outcome = NO_REPLY |
| | 49 | |
| | 50 | // trigger validation if needed |
| | 51 | K = # of SUCCESS results |
| | 52 | if K >= M |
| | 53 | if any result is server_state OVER, outcome SUCCESS, validate_state INIT |
| | 54 | wu.need_validate = true |
| | 55 | |
| | 56 | // check for WU error conditions |
| | 57 | if any result has outcome couldnt_send |
| | 58 | error_mask |= couldnt_send |
| | 59 | K = # results with outcome = client_error |
| | 60 | if K > A |
| | 61 | error_mask |= too_many_error_results |
| | 62 | |
| | 63 | // Note: check on # of success results is done in validator |
| | 64 | |
| | 65 | K = total # results |
| | 66 | if K > B |
| | 67 | error_mask |= too_many_total_results |
| | 68 | |
| | 69 | // if no WU errors, generate new results if needed |
| | 70 | if error_mask == 0 |
| | 71 | K = # results w/ server_state = unsent or in_progress |
| | 72 | L = N - K |
| | 73 | generate L new results |
| | 74 | |
| | 75 | // if WU errors, clean up unsent results |
| | 76 | // and trigger assimilation if needed |
| | 77 | if error_mask |
| | 78 | for all results server_state = unsent |
| | 79 | server_state = over |
| | 80 | outcome = didnt_need |
| | 81 | if wu.assimilate_state == init |
| | 82 | wu.assimilate_state = ready |
| | 83 | |
| | 84 | // if WU is assimilated, trigger deletion of files |
| | 85 | if wu.assimilated_state = DONE |
| | 86 | // trigger input file deletion if needed |
| | 87 | if (all results are OVER and those that are outcome SUCCESS |
| | 88 | have validate_state != INIT) |
| | 89 | wu.file_delete_state = ready |
| | 90 | |
| | 91 | // outputs of error results can be deleted immediately; |
| | 92 | // outputs of successful results can be deleted when validated |
| | 93 | for results of WU |
| | 94 | if canonical result and not all results OVER |
| | 95 | continue |
| | 96 | if outcome = CLIENT_ERROR or (SUCCESS and (VALID or INVALID)) |
| | 97 | if file_delete_state = INIT |
| | 98 | result.file_delete_state = READY |
| | 99 | |
| | 100 | // get next result timeout if any |
| | 101 | transition_time = MAX_INT |
| | 102 | for all results IN_PROGRESS |
| | 103 | transition_time = min(transition_time, result.report_deadline) |
| | 104 | |
| | 105 | // if transitioner is way behind schedule, |
| | 106 | // don't repeatedly handle this WU |
| | 107 | transition_time = max(transition_time, now+delay_bound) |
| | 108 | }}} |
| | 109 | |
| | 110 | === Validator === |
| | 111 | |
| | 112 | {{{ |
| | 113 | for each WU w/ need_validate true |
| | 114 | if have canonical result |
| | 115 | for each result w/ validate_state INIT and outcome SUCCESS |
| | 116 | // possible that we've already deleted canonical output files |
| | 117 | if canonical_result.file_delete_state = DONE |
| | 118 | validate_state = INVALID |
| | 119 | else |
| | 120 | if matches canonical, grant credit |
| | 121 | validate_state = VALID or INVALID |
| | 122 | need_to_handle_over_results = true |
| | 123 | else |
| | 124 | S = set of results w/ outcome SUCCESS |
| | 125 | if consensus(S) |
| | 126 | set canonical_result |
| | 127 | set success results as VALID or INVALID |
| | 128 | grant credit |
| | 129 | need_to_handle_over_results = true |
| | 130 | wu.assimilate_state = READY |
| | 131 | for all results server_state UNSENT |
| | 132 | server_state = OVER |
| | 133 | outcome = DIDNT_NEED |
| | 134 | else |
| | 135 | if # of successful results > C |
| | 136 | wu.error_mask |= too_many_success_result |
| | 137 | need_to_handle_over_results = true |
| | 138 | |
| | 139 | if need_to_handle_over_results: |
| | 140 | wu.transition_time = now |
| | 141 | }}} |
| | 142 | |
| | 143 | === Assimilator === |
| | 144 | |
| | 145 | {{{ |
| | 146 | for each WU with assimilate_state = READY |
| | 147 | call project-specific handler function |
| | 148 | wu.assimilate_state = done |
| | 149 | wu.transition_time = now |
| | 150 | }}} |
