Zabbix/partitioning/CODE_DOCUMENTATION.md

Code Documentation: ZabbixPartitioner

Class: ZabbixPartitioner

Core Methods

__init__(self, config: Dict[str, Any], dry_run: bool = False)

Initializes the partitioner with configuration and runtime mode.

• config: Dictionary containing database connection and partitioning rules.
• dry_run: If True, SQL queries are logged but not executed.

connect_db(self)

Context manager for database connections.

• Handles connection lifecycle (open/close).
• Sets strict session variables:
  • wait_timeout = 86400 (24h) to prevent timeouts during long operations.
  • sql_log_bin = 0 (if configured) to prevent replication of partitioning commands.

run(self, mode: str)

Main entry point for execution.

• mode:
  • 'init': Initial setup. Calls initialize_partitioning.
  • 'maintenance' (default): Routine operation. Calls create_future_partitions and drop_old_partitions.

Logic Methods

initialize_partitioning(table: str, period: str, premake: int, retention_str: str)

Converts a standard table to a partitioned table.

• Strategies (via initial_partitioning_start config):
  • retention: Starts from (Now - Retention). Creates p_archive for older data. FAST.
  • db_min: Queries SELECT MIN(clock). PRECISE but SLOW.

create_future_partitions(table: str, period: str, premake: int)

Ensures sufficient future partitions exist.

• Calculates required partitions based on current time + premake count.
• Checks information_schema for existing partitions.
• Adds missing partitions using ALTER TABLE ... ADD PARTITION.

drop_old_partitions(table: str, period: str, retention_str: str)

Removes partitions older than the retention period.

• Parses partition names (e.g., p2023_01_01) to extract their date.
• Compares against the calculated retention cutoff date.
• Drops qualifiers using ALTER TABLE ... DROP PARTITION.

Helper Methods

get_table_min_clock(table: str) -> Optional[datetime]

• Queries the table for the oldest timestamp. Used in db_min initialization strategy.

has_incompatible_primary_key(table: str) -> bool

• Safety Critical: Verifies that the table's Primary Key includes the clock column.
• Returns True if incompatible (prevents partitioning to avoid MySQL errors).

get_partition_name(dt: datetime, period: str) -> str

• Generates standard partition names:
  • Daily: pYYYY_MM_DD
  • Monthly: pYYYY_MM

get_partition_description(dt: datetime, period: str) -> str

• Generates the VALUES LESS THAN expression for the partition (Start of NEXT period).