[pbs-devel] [PATCH proxmox-backup v8 0/6] closes #3071: maintenance mode for datastore

[Hannes Laimer]

Adds maintenance mode and tracking of active reading/writing operations.
The maintenance mode prevents the start of new operations if the type of
operation they would perform on the datastore would conflict with the
maintenance type that is currently set. This check is performed when
lookup_datastore is called. Tasks only call this function once at the
beginning, therefore updating the maintenance type cannot interfere with
already running tasks.

active operations tracking:
Changed file layout to now also keep track of the pid+starttime and the
counts of operations that that pid started, like this it is possible to
not count operations that were started by a dead process, since they 
are also not active anymore. Whenever the file is updated, also entries
of dead processes are removed. When the file is read, only entries of
active processes are counted.

The UI shows a spinner with the count of conflictintg tasks (the tasks
that were started before the maintenance type was updated) next to it.
As soon as all conflicting tasks are finished a checkmark appears.

v8:
 - replace enum with MaintenanceMode struct
 - impl check function on MaintenanceMode struct
 - api now encodes type+msg in one string
 - message has to be URL encoded to ensure proper parsing
(everywhere except the UI the message has to be already encoded
when passed, API+CLI)

v7:
 - tracking: fix counting on clone
 - ui: correct gettext usages + remove usage of capitalize

v6:
 - also use process start time in order to avoid pid clashes(as suggested
 by Thomas and somehow missed by me in the last version)
 - now a single call of get_active_operations return reads and writes
 - improved code structure
 - don't lock when reading

v5:
 - use simple struct and serde instead of manual parsing for file
 - move tracking related stuff into new file (task_tracking.rs)

v4:
 - clones are not also tracked
 - use lockfile, instead of locking the file
 - track pid of the process which started smth
 - updating maintenance mode is now always possible
 - add get_active_operations endpoint for datastore
 - ui: show count of conflicting tasks (or checkmark if no conflicting
     operations are active)

 v3, based on Dominik Csapak <d.csapak at proxmox.com>'s feedback:
 - added Operation enum(r/w), as suggested by
 - added active operation tracking
 - combine type and message into on field

v2:
 - check for maintenance now directly in lookup_datastore
 - parameter for checking is now the last acceptable maintenance type,
   description in commit msg of 2nd patch
 - ui cleanup

Hannes Laimer (6):
  api-types: add maintenance type
  datastore: add check for maintenance in lookup
  pbs-datastore: add active operations tracking
  api: make maintenance_type updatable
  api: add get_active_operations endpoint
  ui: add option to change the maintenance type

 pbs-api-types/src/datastore.rs       |  26 +++++-
 pbs-api-types/src/lib.rs             |   3 +
 pbs-api-types/src/maintenance.rs     |  78 +++++++++++++++++
 pbs-datastore/Cargo.toml             |   1 +
 pbs-datastore/src/datastore.rs       | 121 +++++++++++++++++++--------
 pbs-datastore/src/lib.rs             |   4 +
 pbs-datastore/src/snapshot_reader.rs |   6 +-
 pbs-datastore/src/task_tracking.rs   | 110 ++++++++++++++++++++++++
 src/api2/admin/datastore.rs          |  81 ++++++++++++------
 src/api2/backup/mod.rs               |   4 +-
 src/api2/config/datastore.rs         |   5 ++
 src/api2/reader/mod.rs               |   6 +-
 src/api2/status.rs                   |   4 +-
 src/api2/tape/backup.rs              |   6 +-
 src/api2/tape/restore.rs             |   6 +-
 src/bin/proxmox-backup-api.rs        |   1 +
 src/bin/proxmox-backup-proxy.rs      |   4 +-
 src/server/mod.rs                    |  16 +++-
 src/server/prune_job.rs              |   4 +-
 src/server/pull.rs                   |   4 +-
 src/server/verify_job.rs             |   4 +-
 www/Makefile                         |   1 +
 www/Utils.js                         |  23 +++++
 www/datastore/OptionView.js          |  30 +++++++
 www/window/MaintenanceOptions.js     |  72 ++++++++++++++++
 25 files changed, 533 insertions(+), 87 deletions(-)
 create mode 100644 pbs-api-types/src/maintenance.rs
 create mode 100644 pbs-datastore/src/task_tracking.rs
 create mode 100644 www/window/MaintenanceOptions.js

-- 
2.30.2