models: replace workflow.run_number with generation and restart number

Change the workflow table to split the run_number into two integers: one
referring to the generation of the workflows, and the other one
referring to the restart number, thus removing the limit of 9 restarts.

Closes reanahub#186.

AUTHORS.rst

@@ -7,6 +7,7 @@ The list of contributors in alphabetical order:
 - `Camila Diaz <https://orcid.org/0000-0001-5543-797X>`_
 - `Diego Rodriguez <https://orcid.org/0000-0003-0649-2002>`_
 - `Dinos Kousidis <https://orcid.org/0000-0002-4914-4289>`_
+- `Giuseppe Steduto <https://orcid.org/0009-0002-1258-8553>`_
 - `Jan Okraska <https://orcid.org/0000-0002-1416-3244>`_
 - `Leticia Wanderley <https://orcid.org/0000-0003-4649-6630>`_
 - `Marco Donadoni <https://orcid.org/0000-0003-2922-5505>`_

CHANGES.rst

@@ -1,6 +1,10 @@
 Changes
 =======
 
+Version 0.9.3 (UNRELEASED)
+--------------------------
+- Replaces ``run_number`` column of the ``Workflow`` table with two new columns ``generation_number`` and ``restart_number``, to allow for more than 9 restarts.
+
 Version 0.9.2 (2023-09-26)
 --------------------------
 

reana_db/alembic/versions/20231002_1208_b85c3e601de4_separate_run_and_restart_number.py

@@ -0,0 +1,114 @@
+"""Separate run number into generation and restart number.
+
+Revision ID: b85c3e601de4
+Revises: 377cfbfccf75
+Create Date: 2023-10-02 12:08:18.292490
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "b85c3e601de4"
+down_revision = "377cfbfccf75"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    """Upgrade to b85c3e601de4 revision."""
+    # Add new columns (generation_number, restart_number)
+    op.add_column(
+        "workflow", sa.Column("generation_number", sa.Integer()), schema="__reana"
+    )
+    op.add_column(
+        "workflow",
+        sa.Column("restart_number", sa.Integer(), default=0),
+        schema="__reana",
+    )
+
+    # Data migration (split run_number into generation_number and restart_number)
+    op.get_bind().execute(
+        sa.text(
+            "UPDATE __reana.workflow"
+            " SET generation_number = FLOOR(run_number), "
+            " restart_number = (run_number - FLOOR(run_number)) * 10"
+        ),
+    )
+
+    # Delete old constraint
+    op.drop_constraint("_user_workflow_run_uc", "workflow", schema="__reana")
+
+    # Drop old run_number column
+    op.drop_column("workflow", "run_number", schema="__reana")
+
+    # Add new constraint (the primary key is not run_number anymore, but with generation and restart number
+    op.create_unique_constraint(
+        "_user_workflow_run_uc",
+        "workflow",
+        ["name", "owner_id", "generation_number", "restart_number"],
+        schema="__reana",
+    )
+
+    # Update restart_number for workflows that have been restarted more than 10 times
+    # (thus erroneously having the following generation_number), in case some of them
+    # were created before the limit on 9 restarts was introduced.
+    op.get_bind().execute(
+        sa.text(
+            """
+            UPDATE __reana.workflow AS w
+            SET
+                generation_number = to_be_updated.new_generation_number,
+                restart_number = (w.restart_number + (w.generation_number - to_be_updated.new_generation_number) * 10)
+            FROM (
+                SELECT MIN(w1.generation_number) - 1 AS new_generation_number, w1.workspace_path
+                FROM __reana.workflow w1
+                WHERE w1.restart AND w1.restart_number = 0
+                GROUP BY w1.workspace_path
+            ) AS to_be_updated
+            WHERE w.workspace_path = to_be_updated.workspace_path
+            """
+        ),
+    )
+
+
+def downgrade():
+    """Downgrade to 377cfbfccf75 revision."""
+    # Revert constraint
+    op.drop_constraint("_user_workflow_run_uc", "workflow", schema="__reana")
+
+    # Add old run_number column back
+    op.add_column("workflow", sa.Column("run_number", sa.Float()), schema="__reana")
+
+    # Check that there are no workflows discarded more than 10 times
+    # This is because of the way the info about restarts is stored in
+    # the run_number column (see https://github.com/reanahub/reana-db/issues/186)
+    restarted_ten_times = (
+        op.get_bind()
+        .execute("SELECT COUNT(*) FROM __reana.workflow WHERE restart_number >= 10")
+        .fetchone()[0]
+    )
+    if restarted_ten_times != 0:
+        raise ValueError(
+            "Cannot migrate database because some workflows have been restarted 10 or more times,"
+            " and the previous database revision only supports up to 9 restarts."
+            " If you want to downgrade, you should manually delete them."
+        )
+
+    # Data migration (combine generation_number and restart_number back to run_number)
+    op.get_bind().execute(
+        "UPDATE __reana.workflow SET run_number=generation_number+(restart_number * 1.0 /10)"
+    )
+
+    # Drop new columns
+    op.drop_column("workflow", "generation_number", schema="__reana")
+    op.drop_column("workflow", "restart_number", schema="__reana")
+
+    # Restore old constraint
+    op.create_unique_constraint(
+        "_user_workflow_run_uc",
+        "workflow",
+        ["name", "owner_id", "run_number"],
+        schema="__reana",
+    )

reana_db/config.py

@@ -85,6 +85,3 @@
     os.getenv("REANA_PERIODIC_RESOURCE_QUOTA_UPDATE_POLICY", "false")
 )
 """Whether to run the periodic (cronjob) resource quota updater."""
-
-LIMIT_RESTARTS = 9
-"""Maximum number of times a workflow can be restarted."""

reana_db/models.py

@@ -16,7 +16,7 @@
 import uuid
 from datetime import datetime
 from functools import reduce
-from typing import Dict, List
+from typing import Dict, List, Tuple
 
 from reana_commons.config import (
     MQ_MAX_PRIORITY,
@@ -54,12 +54,12 @@
     DB_SECRET_KEY,
     DEFAULT_QUOTA_LIMITS,
     DEFAULT_QUOTA_RESOURCES,
-    LIMIT_RESTARTS,
     WORKFLOW_TERMINATION_QUOTA_UPDATE_POLICY,
 )
 from reana_db.utils import (
     build_workspace_path,
     store_workflow_disk_quota,
+    split_run_number,
     update_users_cpu_quota,
     update_users_disk_quota,
     update_workflow_cpu_quota,
@@ -459,7 +459,8 @@ class Workflow(Base, Timestamp, QuotaBase):
     run_started_at = Column(DateTime)
     run_finished_at = Column(DateTime)
     run_stopped_at = Column(DateTime)
-    _run_number = Column("run_number", Float)
+    generation_number = Column(Integer)
+    restart_number = Column(Integer, default=0)
     job_progress = Column(JSONType, default=dict)
     workspace_path = Column(String)
     restart = Column(Boolean, default=False)
@@ -487,7 +488,11 @@ class Workflow(Base, Timestamp, QuotaBase):
 
     __table_args__ = (
         UniqueConstraint(
-            "name", "owner_id", "run_number", name="_user_workflow_run_uc"
+            "name",
+            "owner_id",
+            "generation_number",
+            "restart_number",
+            name="_user_workflow_run_uc",
         ),
         {"schema": "__reana"},
     )
@@ -527,7 +532,9 @@ def __init__(
         self.git_repo = git_repo
         self.git_provider = git_provider
         self.restart = restart
-        self._run_number = self.assign_run_number(run_number)
+        self.generation_number, self.restart_number = self.get_new_run_number(
+            run_number
+        )
         self.workspace_path = workspace_path or build_workspace_path(
             self.owner_id, self.id_
         )
@@ -538,53 +545,65 @@ def __repr__(self):
         return "<Workflow %r>" % self.id_
 
     @hybrid_property
-    def run_number(self):
+    def run_number(self) -> str:
         """Property of run_number."""
-        if self._run_number.is_integer():
-            return int(self._run_number)
-        return self._run_number
-
-    @run_number.expression
-    def run_number(cls):
-        return func.abs(cls._run_number)
+        if self.restart_number != 0:
+            return f"{self.generation_number}.{self.restart_number}"
+        return str(self.generation_number)
 
-    def assign_run_number(self, run_number):
-        """Assing run number."""
+    def _get_last_workflow(self, run_number):
+        """Fetch the last workflow restart given a certain run number."""
         from .database import Session
 
         if run_number:
+            generation_number, restart_number = split_run_number(run_number)
             last_workflow = (
                 Session.query(Workflow)
                 .filter(
                     Workflow.name == self.name,
-                    Workflow.run_number >= int(run_number),
-                    Workflow.run_number < int(run_number) + 1,
+                    Workflow.generation_number == generation_number,
                     Workflow.owner_id == self.owner_id,
                 )
-                .order_by(Workflow.run_number.desc())
+                .order_by(
+                    Workflow.generation_number.desc(), Workflow.restart_number.desc()
+                )
                 .first()
             )
         else:
             last_workflow = (
                 Session.query(Workflow)
                 .filter_by(name=self.name, restart=False, owner_id=self.owner_id)
-                .order_by(Workflow.run_number.desc())
+                .order_by(
+                    Workflow.generation_number.desc(), Workflow.restart_number.desc()
+                )
                 .first()
             )
-        if last_workflow and self.restart:
-            # FIXME: remove the limit of nine restarts when we fix the way in which
-            # we save `run_number` in the DB
-            num_restarts = round(last_workflow.run_number * 10) % 10
-            if num_restarts == LIMIT_RESTARTS:
+        return last_workflow
+
+    def get_new_run_number(self, run_number) -> Tuple[int, int]:
+        """Return the generation and restart numbers for a new workflow.
+
+        Return a tuple where the first element is the generation number and the
+        second element is the restart number.
+        """
+        last_workflow = self._get_last_workflow(run_number)
+
+        if not last_workflow:
+            if self.restart:
                 raise REANAValidationError(
-                    f"Cannot restart a workflow more than {LIMIT_RESTARTS} times"
+                    "Cannot restart a workflow that has not been run before."
                 )
-            return round(last_workflow.run_number + 0.1, 1)
+            return 1, 0  # First generation, no restart
+
         else:
-            if not last_workflow:
-                return 1
+            if not self.restart:
+                generation_number = last_workflow.generation_number + 1
+                restart_number = 0
             else:
-                return last_workflow.run_number + 1
+                generation_number = last_workflow.generation_number
+                restart_number = last_workflow.restart_number + 1
+
+            return generation_number, restart_number
 
     def get_input_parameters(self):
         """Return workflow parameters."""
@@ -604,7 +623,7 @@ def get_owner_access_token(self):
 
     def get_full_workflow_name(self):
         """Return full workflow name including run number."""
-        return "{}.{}".format(self.name, str(self.run_number))
+        return "{}.{}".format(self.name, self.run_number)
 
     def get_workspace_disk_usage(self, summarize=False, search=None):
         """Retrieve disk usage information of a workspace."""
@@ -643,15 +662,13 @@ def get_all_restarts(self):
         """Get all the restarts of this workflow, including the original workflow.
 
         Returns all the restarts of this workflow, that is all the workflows that have
-        the same name and the same run number (up to the dot). This includes the
+        the same name and the same generation number. This includes the
         original workflow, as well as all the following restarts.
         """
-        run_number = int(self.run_number)
         restarts = Workflow.query.filter(
             Workflow.name == self.name,
             Workflow.owner_id == self.owner_id,
-            Workflow.run_number >= run_number,
-            Workflow.run_number < run_number + 1,
+            Workflow.generation_number == self.generation_number,
         )
         return restarts
 

reana_db/utils.py

@@ -52,6 +52,14 @@ def build_workspace_path(user_id, workflow_id=None, workspace_root_path=None):
     return workspace_path
 
 
+def split_run_number(run_number):
+    """Split run number into generation and restart numbers."""
+    run_number = str(run_number)
+    if "." in run_number:
+        return tuple(map(int, run_number.split(".", maxsplit=1)))
+    return int(run_number), 0
+
+
 def _get_workflow_with_uuid_or_name(uuid_or_name, user_uuid):
     """Get Workflow from database with uuid or name.
 
@@ -128,21 +136,31 @@ def _get_workflow_with_uuid_or_name(uuid_or_name, user_uuid):
             return _get_workflow_by_name(workflow_name, user_uuid)
 
         # `run_number` was specified.
-        # Check `run_number` is valid.
         try:
-            run_number = float(run_number)
+            generation_number, restart_number = run_number.split(".", maxsplit=1)
+        except ValueError:
+            # There were not enough dot-separated substrings, so probably
+            # the `restart_number` was not specified.
+            generation_number = run_number
+            restart_number = 0
+
+        # Check `run_number` and `restart_number` are valid.
+        try:
+            generation_number = int(generation_number)
+            restart_number = int(restart_number)
         except ValueError:
-            # `uuid_or_name` was split, so it is a dot-separated string
+            # `uuid_or_name` was split, so it is a dot-separated string,
             # but it didn't contain a valid `run_number`.
             # Assume that this dot-separated string is the name of
             # the workflow and search with it.
             return _get_workflow_by_name(uuid_or_name, user_uuid)
 
         # `run_number` is valid.
-        # Search by `run_number` since it is a primary key.
+        # Search by `generation_number` and `restart_number`, since it is a primary key.
         workflow = Workflow.query.filter(
             Workflow.name == workflow_name,
-            Workflow.run_number == run_number,
+            Workflow.generation_number == generation_number,
+            Workflow.restart_number == restart_number,
             Workflow.owner_id == user_uuid,
         ).one_or_none()
         if not workflow:
@@ -169,7 +187,7 @@ def _get_workflow_by_name(workflow_name, user_uuid):
         Workflow.query.filter(
             Workflow.name == workflow_name, Workflow.owner_id == user_uuid
         )
-        .order_by(Workflow.run_number.desc())
+        .order_by(Workflow.generation_number.desc(), Workflow.restart_number.desc())
         .first()
     )
     if not workflow: