Yeah, thanks for the info. See: https://github.com/ceph/ceph/pull/25632 While the bug is still valid, note that there are easier ways to implement the code that triggered it. For example we could use a JSONFormattable object to parse the json and then we'd have a dict-like access to the fields. Or instead of iterating over the different array elements and then decoding the specific field, we could use the existing struct (or define a new one) that defined the structure and json-decode the entire array (or even the entire message). Thanks, Yehuda On Tue, Dec 18, 2018 at 7:13 PM David Zafman <dzafman@xxxxxxxxxx> wrote: > > > Yehuda, > > http://tracker.ceph.com/issues/37706 > > https://github.com/ceph/ceph/pull/23298 > > Something in the JSONParser is broken probably due to changes to > src/common/ceph_json.cc. > > The function get_inconsistent_pgs() is unchanged and was working > properly until recently. > > int librados::RadosClient::get_inconsistent_pgs(int64_t pool_id, > std::vector<std::string>* pgs) > { > vector<string> cmd = { > "{\"prefix\": \"pg ls\"," > "\"pool\": " + std::to_string(pool_id) + "," > "\"states\": [\"inconsistent\"]," > "\"format\": \"json\"}" > }; > bufferlist inbl, outbl; > string outstring; > if (auto ret = mgr_command(cmd, inbl, &outbl, &outstring); ret) { > return ret; > } > if (!outbl.length()) { > // no pg returned > return 0; > } > JSONParser parser; > if (!parser.parse(outbl.c_str(), outbl.length())) { <<<< After this > parse() the pg_stats value is an empty string > return -EINVAL; > } > vector<string> v; > if (!parser.is_array()) { > JSONObj *pgstat_obj = parser.find_obj("pg_stats"); > if (!pgstat_obj) > return 0; > auto s = pgstat_obj->get_data(); <<<<<< s is a string but it is > empty, but should contain the array from here: [ { "pgid":"1.0", "... > JSONParser pg_stats; > if (!pg_stats.parse(s.c_str(), s.length())) { > return -EINVAL; <<<<<< This is returned to the caller > } > v = pg_stats.get_array_elements(); > } else { > v = parser.get_array_elements(); > } > for (auto i : v) { > JSONParser pg_json; > if (!pg_json.parse(i.c_str(), i.length())) { > return -EINVAL; > } > string pgid; > JSONDecoder::decode_json("pgid", pgid, &pg_json); > pgs->emplace_back(std::move(pgid)); > } > return 0; > } > > This is json being parsed in one test case: > > {"pg_ready":true, "pg_stats":[ { "pgid":"1.0", > "version":"16'56","reported_seq":"62","reported_epoch":"20","state":"active+clean+inconsistent","last_fresh":"2018-12-18 > 15:21:22.173804","last_change":"2018-12-18 > 15:21:22.173804","last_active":"2018-12-18 > 15:21:22.173804","last_peered":"2018-12-18 > 15:21:22.173804","last_clean":"2018-12-18 > 15:21:22.173804","last_became_active":"2018-12-18 > 15:21:21.347685","last_became_peered":"2018-12-18 > 15:21:21.347685","last_unstale":"2018-12-18 > 15:21:22.173804","last_undegraded":"2018-12-18 > 15:21:22.173804","last_fullsized":"2018-12-18 > 15:21:22.173804","mapping_epoch":19,"log_start":"0'0","ondisk_log_start":"0'0","created":7,"last_epoch_clean":20,"parent":"0.0","parent_split_bits":0,"last_scrub":"16'56","last_scrub_stamp":"2018-12-18 > 15:21:22.173684","last_deep_scrub":"0'0","last_deep_scrub_stamp":"2018-12-18 > 15:21:06.514438","last_clean_scrub_stamp":"2018-12-18 > 15:21:06.514438","log_size":56,"ondisk_log_size":56,"stats_invalid":false,"dirty_stats_invalid":false,"omap_stats_invalid":false,"hitset_stats_invalid":false,"hitset_bytes_stats_invalid":false,"pin_stats_invalid":false,"manifest_stats_invalid":false,"snaptrimq_len":0,"stat_sum":{"num_bytes":24448,"num_objects":36,"num_object_clones":20,"num_object_copies":36,"num_objects_missing_on_primary":0,"num_objects_missing":0,"num_objects_degraded":0,"num_objects_misplaced":0,"num_objects_unfound":0,"num_objects_dirty":36,"num_whiteouts":3,"num_read":0,"num_read_kb":0,"num_write":36,"num_write_kb":50,"num_scrub_errors":20,"num_shallow_scrub_errors":20,"num_deep_scrub_errors":0,"num_objects_recovered":0,"num_bytes_recovered":0,"num_keys_recovered":0,"num_objects_omap":0,"num_objects_hit_set_archive":0,"num_bytes_hit_set_archive":0,"num_flush":0,"num_flush_kb":0,"num_evict":0,"num_evict_kb":0,"num_promote":0,"num_flush_mode_high":0,"num_flush_mode_low":0,"num_evict_mode_some":0,"num_evict_mode_full":0,"num_objects_pinned":0,"num_legacy_snapsets":0,"num_large_omap_objects":0,"num_objects_manifest":0},"up":[0],"acting":[0],"blocked_by":[],"up_primary":0,"acting_primary":0,"purged_snaps":[] > }]} > > > David Zafman > >
