apache气流：initdb vs resetdb

Question

“airflow initdb”命令和“airflow resetdb”命令有什么区别？

真的有必要有两个不同的命令吗？

什么时候适合使用一个与另一个？

doc 说...

airflow initdb：初始化元数据库

airflow resetdb：烧毁并重建元数据库

这并不能告诉我太多。

我最好的猜测是

airflow initdb 仅在第一次从airflow.cfg 创建数据库时使用
airflow resetdb 如果对该配置是必需的。

当我运行它们时，不会更改 sqlite 数据库上的时间戳，但 resetdb 似乎更嘈杂。

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。
目前还不清楚哪种情况适合这种情况。
也不清楚 webserver 和 scheduler 是如何知道去哪里寻找配置的？
也许他们先查看airflow.cfg 以找出数据库在哪里，然后再查看数据库？这似乎是多余的。

Answer 1

db reset 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。

db init 仅在安装气流时运行一次。

一般来说，我们不太担心 dag 奔跑。但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，出于安全最佳实践的考虑，这些数据可能不会被复制。

db init 也是幂等的，因此可以随意运行，无需担心数据库更改。

Answer 2

上面的解释是对的，但是命令是错误的。 重置的工作命令是 - airflow db reset init (set db) 的工作命令是 - airflow db init