CONFIG 语法

Nebula Graph 使用 gflags 进行运行时配置。

gflags 参数

相关的 gflags 参数有四个，其中，max_edge_returned_per_vertex 用来控制一个点最多可以搜索返回的边数，rocksdb_db_options，rocksdb_column_family_options，rocksdb_block_based_table_options 三个参数均为 json 格式，其中每个参数 key 和 value 均为 string 格式。例如可以在 storage 的 conf 文件中做如下设置：

  1.     rocksdb_db_options = {"stats_dump_period_sec":"200", "enable_write_thread_adaptive_yield":"false", "write_thread_max_yield_usec":"600",
  2.     "max_edge_returned_per_vertex":"INT_MAX"}
  3.     rocksdb_column_family_options = {"max_write_buffer_number":"4", "min_write_buffer_number_to_merge":"2", "max_write_buffer_number_to_maintain":"1"}
  4.     rocksdb_block_based_table_options = {"block_restart_interval":"2"}

另外目前支持动态修改 storage service 的部分 rocksdb 参数, 如下

  1.     // rocksdb_column_family_options
  2.     max_write_buffer_number
  3.     level0_file_num_compaction_trigger
  4.     level0_slowdown_writes_trigger
  5.     level0_stop_writes_trigger
  6.     target_file_size_base
  7.     target_file_size_multiplier
  8.     max_bytes_for_level_base
  9.     max_bytes_for_level_multiplier
  10.     ttl
  11.     disable_auto_compactions
  13.     // rocksdb_db_options
  14.     max_total_wal_size
  15.     delete_obsolete_files_period_micros
  16.     max_background_jobs
  17.     base_background_compactions
  18.     max_background_compactions
  19.     stats_dump_period_sec
  20.     compaction_readahead_size
  21.     writable_file_max_buffer_size
  22.     bytes_per_sync
  23.     wal_bytes_per_sync
  24.     delayed_write_rate
  25.     avoid_flush_during_shutdown
  26.     max_open_files

示例

  1. nebula> UPDATE CONFIGS storage:rocksdb_column_family_options = \
  2.         { disable_auto_compactions = false ,         level0_file_num_compaction_trigger = 10 }

显示变量

  1. SHOW CONFIGS [graph|meta|storage]

例如

  1. nebula> SHOW CONFIGS meta
  2. ============================================================================================================================
  3. | module | name                                        | type   | mode      | value                                        |
  4. ============================================================================================================================
  5. | META   | v                                           | INT64  | IMMUTABLE | 4                                            |
  6. ----------------------------------------------------------------------------------------------------------------------------
  7. | META   | help                                        | BOOL   | IMMUTABLE | False                                        |
  8. ----------------------------------------------------------------------------------------------------------------------------
  9. | META   | port                                        | INT64  | IMMUTABLE | 45500                                        |
  10. ----------------------------------------------------------------------------------------------------------------------------

获取变量

  1. GET CONFIGS [graph|meta|storage :] var

例如

  1. nebula> GET CONFIGS storage:load_data_interval_secs
  2. =================================================================
  3. | module  | name                      | type  | mode    | value |
  4. =================================================================
  5. | STORAGE | load_data_interval_secs   | INT64 | MUTABLE | 120   |
  6. -----------------------------------------------------------------
  1. nebula> GET CONFIGS load_data_interval_secs
  2. =================================================================
  3. | module  | name                    | type  | mode      | value |
  4. =================================================================
  5. | GRAPH   | load_data_interval_secs | INT64 | MUTABLE   | 120   |
  6. -----------------------------------------------------------------
  7. | META    | load_data_interval_secs | INT64 | IMMUTABLE | 120   |
  8. -----------------------------------------------------------------
  9. | STORAGE | load_data_interval_secs | INT64 | MUTABLE   | 120   |
  10. -----------------------------------------------------------------
  11. Got 3 rows (Time spent: 1449/2339 us)

更新变量

  1. UPDATE CONFIGS [graph|meta|storage :] var = value

更新的变量将永久存储于 meta-service 中。 如果变量模式为 MUTABLE，更改会即时生效。如果模式为 REBOOT，更改在服务器重启后生效。 支持在 UPDATE CONFIGS 中使用算式。

例如

  1. nebula> UPDATE CONFIGS storage:load_data_interval_secs=1
  2. Execution succeeded (Time spent: 1750/2484 us)
  3. nebula> GET CONFIGS storage:load_data_interval_secs
  4. ===============================================================
  5. | module  | name                    | type  | mode    | value |
  6. ===============================================================
  7. | STORAGE | load_data_interval_secs | INT64 | MUTABLE | 1     |
  8. ---------------------------------------------------------------
  9. Got 1 rows (Time spent: 1678/3420 us)