chore(clickhouse): limit number of concurrent connections for backup

[jakubno]

No description provided.

[cursor]

PR Summary

Medium Risk
Limits ClickHouse backup concurrency, which could reduce load but may also slow backups or cause unexpected behavior if altinity/clickhouse-backup interprets the env var differently than expected.

Overview
Sets CLICKHOUSE_MAX_CONNECTIONS=2 for the clickhouse-backup batch job, capping concurrent connections used during create_remote backups to reduce pressure on the ClickHouse server while the periodic backup runs.

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[claude]

LGTM — straightforward config change adding a connection limit for the ClickHouse backup job.

Extended reasoning...

Overview

Adds a single environment variable CLICKHOUSE_MAX_CONNECTIONS=2 to the clickhouse-backup batch job's Nomad HCL config. The rest of the diff is whitespace alignment.

Security Risks

None. This is a tuning parameter for an internal backup job; no auth, crypto, or permissions code is touched.

Level of Scrutiny

Low. This is a one-line operational config change to a batch job that runs periodically. The variable is a well-known setting for altinity/clickhouse-backup to cap concurrent ClickHouse connections, reducing server pressure during backups.

Other Factors

No bugs were reported by the bug hunting system. The change is consistent with the existing pattern of env-var configuration in this file and has a clear operational motivation.