apache 气流：initdb 与 resetdb

Question

“airflow initdb”命令和“airflow resetdb”命令之间究竟有什么区别？

真的有必要有 2 个不同的命令吗？

什么时候使用一种和另一种比较合适？

该文档称...

气流 initdb : 初始化元数据数据库

气流 resetdb：烧毁并重建元数据数据库

这并没有告诉我太多。

我最好的猜测是

气流 initdb仅在第一次从
气流创建数据库时使用。如果需要对该配置进行任何更改，则将使用气流 resetdb。

当我运行它们时，它们都不会改变 sqlite 数据库上的时间戳，但 resetdb 似乎更加嘈杂。

气流初始化数据库：

(.sandbox) [airflow@localhost airflow]$ airflow initdb
[2020-01-01 21:49:21,603] {settings.py:252} INFO - settings.configure_orm(): Using pool settings. pool_size=5, max_overflow=10, pool_recycle=1800, pid=24917
DB: postgresql+psycopg2://airflow@localhost:5432/airflow_mdb
[2020-01-01 21:49:22,257] {db.py:368} INFO - Creating tables
INFO  [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO  [alembic.runtime.migration] Will assume transactional DDL.
Done.

气流重置数据库：

(.sandbox) [airflow@localhost airflow]$ airflow resetdb
[2020-01-01 21:49:46,579] {settings.py:252} INFO - settings.configure_orm(): Using pool settings. pool_size=5, max_overflow=10, pool_recycle=1800, pid=25045
DB: postgresql+psycopg2://airflow@localhost:5432/airflow_mdb
This will drop existing tables if they exist. Proceed? (y/n)y
[2020-01-01 21:49:49,984] {db.py:389} INFO - Dropping tables that exist
[2020-01-01 21:49:50,062] {migration.py:154} INFO - Context impl PostgresqlImpl.
[2020-01-01 21:49:50,063] {migration.py:161} INFO - Will assume transactional DDL.
[2020-01-01 21:49:50,070] {db.py:368} INFO - Creating tables
INFO  [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO  [alembic.runtime.migration] Will assume transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> e3a246e0dc1, current schema
INFO  [alembic.runtime.migration] Running upgrade e3a246e0dc1 -> 1507a7289a2f, create is_encrypted
INFO  [alembic.runtime.migration] Running upgrade 1507a7289a2f -> 13eb55f81627, maintain history for compatibility with earlier migrations
INFO  [alembic.runtime.migration] Running upgrade 13eb55f81627 -> 338e90f54d61, More logging into task_instance
INFO  [alembic.runtime.migration] Running upgrade 338e90f54d61 -> 52d714495f0, job_id indices
INFO  [alembic.runtime.migration] Running upgrade 52d714495f0 -> 502898887f84, Adding extra to Log
INFO  [alembic.runtime.migration] Running upgrade 502898887f84 -> 1b38cef5b76e, add dagrun
INFO  [alembic.runtime.migration] Running upgrade 1b38cef5b76e -> 2e541a1dcfed, task_duration
INFO  [alembic.runtime.migration] Running upgrade 2e541a1dcfed -> 40e67319e3a9, dagrun_config
INFO  [alembic.runtime.migration] Running upgrade 40e67319e3a9 -> 561833c1c74b, add password column to user
INFO  [alembic.runtime.migration] Running upgrade 561833c1c74b -> 4446e08588, dagrun start end
INFO  [alembic.runtime.migration] Running upgrade 4446e08588 -> bbc73705a13e, Add notification_sent column to sla_miss
INFO  [alembic.runtime.migration] Running upgrade bbc73705a13e -> bba5a7cfc896, Add a column to track the encryption state of the 'Extra' field in connection
INFO  [alembic.runtime.migration] Running upgrade bba5a7cfc896 -> 1968acfc09e3, add is_encrypted column to variable table
INFO  [alembic.runtime.migration] Running upgrade 1968acfc09e3 -> 2e82aab8ef20, rename user table
INFO  [alembic.runtime.migration] Running upgrade 2e82aab8ef20 -> 211e584da130, add TI state index
INFO  [alembic.runtime.migration] Running upgrade 211e584da130 -> 64de9cddf6c9, add task fails journal table
INFO  [alembic.runtime.migration] Running upgrade 64de9cddf6c9 -> f2ca10b85618, add dag_stats table
INFO  [alembic.runtime.migration] Running upgrade f2ca10b85618 -> 4addfa1236f1, Add fractional seconds to mysql tables
INFO  [alembic.runtime.migration] Running upgrade 4addfa1236f1 -> 8504051e801b, xcom dag task indices
INFO  [alembic.runtime.migration] Running upgrade 8504051e801b -> 5e7d17757c7a, add pid field to TaskInstance
INFO  [alembic.runtime.migration] Running upgrade 5e7d17757c7a -> 127d2bf2dfa7, Add dag_id/state index on dag_run table
INFO  [alembic.runtime.migration] Running upgrade 127d2bf2dfa7 -> cc1e65623dc7, add max tries column to task instance
INFO  [alembic.runtime.migration] Running upgrade cc1e65623dc7 -> bdaa763e6c56, Make xcom value column a large binary
INFO  [alembic.runtime.migration] Running upgrade bdaa763e6c56 -> 947454bf1dff, add ti job_id index
INFO  [alembic.runtime.migration] Running upgrade 947454bf1dff -> d2ae31099d61, Increase text size for MySQL (not relevant for other DBs' text types)
INFO  [alembic.runtime.migration] Running upgrade d2ae31099d61 -> 0e2a74e0fc9f, Add time zone awareness
INFO  [alembic.runtime.migration] Running upgrade d2ae31099d61 -> 33ae817a1ff4, kubernetes_resource_checkpointing
INFO  [alembic.runtime.migration] Running upgrade 33ae817a1ff4 -> 27c6a30d7c24, kubernetes_resource_checkpointing
INFO  [alembic.runtime.migration] Running upgrade 27c6a30d7c24 -> 86770d1215c0, add kubernetes scheduler uniqueness
INFO  [alembic.runtime.migration] Running upgrade 86770d1215c0, 0e2a74e0fc9f -> 05f30312d566, merge heads
INFO  [alembic.runtime.migration] Running upgrade 05f30312d566 -> f23433877c24, fix mysql not null constraint
INFO  [alembic.runtime.migration] Running upgrade f23433877c24 -> 856955da8476, fix sqlite foreign key
INFO  [alembic.runtime.migration] Running upgrade 856955da8476 -> 9635ae0956e7, index-faskfail
INFO  [alembic.runtime.migration] Running upgrade 9635ae0956e7 -> dd25f486b8ea, add idx_log_dag
INFO  [alembic.runtime.migration] Running upgrade dd25f486b8ea -> bf00311e1990, add index to taskinstance
INFO  [alembic.runtime.migration] Running upgrade 9635ae0956e7 -> 0a2a5b66e19d, add task_reschedule table
INFO  [alembic.runtime.migration] Running upgrade 0a2a5b66e19d, bf00311e1990 -> 03bc53e68815, merge_heads_2
INFO  [alembic.runtime.migration] Running upgrade 03bc53e68815 -> 41f5f12752f8, add superuser field
INFO  [alembic.runtime.migration] Running upgrade 41f5f12752f8 -> c8ffec048a3b, add fields to dag
INFO  [alembic.runtime.migration] Running upgrade c8ffec048a3b -> dd4ecb8fbee3, Add schedule interval to dag
INFO  [alembic.runtime.migration] Running upgrade dd4ecb8fbee3 -> 939bb1e647c8, task reschedule fk on cascade delete
INFO  [alembic.runtime.migration] Running upgrade c8ffec048a3b -> a56c9515abdc, Remove dag_stat table
INFO  [alembic.runtime.migration] Running upgrade 939bb1e647c8 -> 6e96a59344a4, Make TaskInstance.pool not nullable
INFO  [alembic.runtime.migration] Running upgrade 6e96a59344a4 -> 74effc47d867, change datetime to datetime2(6) on MSSQL tables
INFO  [alembic.runtime.migration] Running upgrade 939bb1e647c8 -> 004c1210f153, increase queue name size limit
(.sandbox) [airflow@localhost airflow]$ 

当然，您可以将数据库从 sqlite 移动到 postgres。
目前尚不清楚哪种情况适合这种情况。
还不清楚网络服务器和调度程序如何知道在哪里查找配置？
也许他们先查看airflow.cfg 找出数据库在哪里，然后再查看数据库？这似乎是多余的。

Answer 1

resetdb将从元数据数据库中删除所有条目。这包括所有 dag 运行、变量和连接。

initdb 安装气流后，仅运行一次。

一般来说，我们不太担心 dag 运行。但是重新创建变量和连接可能会很烦人，因为它们通常包含秘密和敏感数据，根据安全最佳实践，这些数据可能不会被复制。

initdb 也是幂等的，因此可以根据您选择的频率运行它，而无需担心数据库更改。