Redundant database

From VoIPmonitor.org


This guide covers methods for replicating, synchronizing, and migrating the VoIPmonitor CDR database between instances.

Overview

VoIPmonitor offers the following methods for CDR synchronization:

Method Description Use Case
Database Backup Mode Dedicated sniffer reads from source DB, writes to destination DB Online migration, read-only replicas, hot-standby
Master-Master Replication Bidirectional MySQL/MariaDB replication Full HA with automatic failover (see Master-Master Replication)

ℹ️ Note: Both methods synchronize CDR data only. GUI settings (users, alerts, capture rules) must be migrated separately via Tools → Backup & Restore.

Database Backup Mode

A dedicated VoIPmonitor instance reads CDRs from a source database and writes them to a destination database. This is the recommended method for online GUI migration.

Architecture

Online GUI Migration Workflow

  1. Install VoIPmonitor GUI on the new server with a fresh database
  2. Backup configuration: On old GUI → Tools → Backup & Restore → backup configuration tables
  3. Restore configuration: On new GUI → upload the backup file (do this BEFORE starting migration)
  4. Create migration config file (see below)
  5. Start migration instance
  6. Once replication catches up, switch users to the new GUI
  7. Stop migration instance and decommission old server

Configuration

Copy the original config and modify for migration mode: 

scp root@old-server:/etc/voipmonitor.conf /etc/voipmonitor-migrate.conf

Required modifications in /etc/voipmonitor-migrate.conf: 

# 1. Avoid port conflict with production sniffer
managerport = 5030

# 2. DISABLE packet capture (comment out all interface lines)
# interface = eth0

# 3. Destination Database (NEW server - local)
mysqlhost      = 127.0.0.1
mysqldb        = voipmonitor
mysqlusername  = root
mysqlpassword  = new_password

# 4. Source Database (OLD server - remote)
database_backup_from_mysqlhost     = 192.168.0.1
database_backup_from_mysqldb       = voipmonitor
database_backup_from_mysqlusername = root
database_backup_from_mysqlpassword = old_password

# 5. Start date for replication
database_backup_from_date = 2024-01-01

# 6. CRITICAL: Pre-create partitions for historical dates
# Must match (or be earlier than) database_backup_from_date above.
# Without this, all migrated CDRs land in a single partition and
# cleandatabase cannot DROP old partitions by calldate.
create_old_partitions_from = 2024-01-01

# Alternative: create partitions for the last N days
# create_old_partitions = 365

# 7. Performance tuning
database_backup_insert_threads = 3   # Higher = faster but more load
database_backup_pause          = 3   # Higher = less load on source DB

⚠️ Warning: Partitions must exist for all migrated dates before migration starts. By default, VoIPmonitor only creates partitions for the current day and create_new_partitions days ahead (default: 2). If historical CDRs are inserted without matching partitions, they all end up in a single partition — and cleandatabase (which uses DROP PARTITION by calldate) will no longer be able to remove old data selectively. Always set create_old_partitions_from to the same date as database_backup_from_date.

Verify partitions after first start: 

SELECT PARTITION_NAME, PARTITION_DESCRIPTION
FROM information_schema.PARTITIONS
WHERE TABLE_NAME = 'cdr'
ORDER BY PARTITION_ORDINAL_POSITION
LIMIT 10;

Parameter Reference:

Parameter Description
database_backup_from_date Start date for sync (YYYY-MM-DD)
create_old_partitions_from (Critical for migration) Create partitions from this date (YYYY-MM-DD). Should match database_backup_from_date.
create_old_partitions Alternative: create partitions for the last N days (integer)
database_backup_insert_threads Parallel write threads (higher = faster, more load)
database_backup_pause Seconds between batches (higher = gentler on source DB)
database_backup_desc_dir Set yes allow write new CDRs to destination db instead of to sourcedb

Running the Migration

Test manually first: 

voipmonitor --config-file /etc/voipmonitor-migrate.conf -k -v 1

Run as systemd service:

Create /etc/systemd/system/voipmonitor-migrate.service: 

[Unit]
Description=VoIPmonitor Database Migration
After=network.target mysql.service

[Service]
Type=simple
ExecStart=/usr/local/sbin/voipmonitor -c /etc/voipmonitor-migrate.conf
Restart=on-failure

[Install]
WantedBy=multi-user.target

systemctl daemon-reload
systemctl enable --now voipmonitor-migrate

Migrating PCAP Files

Database migration does NOT include PCAP files. Migrate separately using rsync: 

rsync -avz root@old-server:/var/spool/voipmonitor/ /var/spool/voipmonitor/

⚠️ Warning: Timezone must match between servers. PCAP paths use local timezone (spooldir/YYYY-MM-DD/HH/MM/). Mismatched timezones cause GUI to fail finding historical PCAPs. 

# Check timezone
timedatectl

# Set timezone
timedatectl set-timezone Europe/Prague

Schema Compatibility

The migration instance automatically handles database schema upgrades. This is useful when:

  • Migrating to different MySQL/MariaDB versions
  • Upgrading VoIPmonitor versions during migration
  • Moving from local MySQL to remote Percona

To identify schema changes manually: 

systemctl restart voipmonitor
tail -f /var/log/voipmonitor/voipmonitor.log | grep -E "CLI|ALTER|CREATE TABLE"

⚠️ Warning: For cross-version migration (e.g., MySQL 5.7 to 8.0), use the migration instance method instead of mysqldump. It handles schema differences automatically.

See Also


AI Summary for RAG

Summary: VoIPmonitor supports two methods for CDR database redundancy: (1) Database Backup Mode — a dedicated migration instance reads CDRs from source DB and writes to destination using database_backup_from_* parameters, recommended for online server migration; (2) Master-Master MySQL replication for full HA. GUI settings migrate separately via Backup & Restore. PCAP files require separate rsync migration with matching timezones.

Keywords: database backup, migration, redundant database, CDR replication, database_backup_from_mysqlhost, database_backup_from_date, database_backup_insert_threads, database_backup_pause, voipmonitor-migrate.conf, PCAP migration, rsync, timezone, master-master replication, high availability

Key Questions:

  • How to migrate VoIPmonitor database to a new server?
  • What are the database_backup_from parameters for database migration?
  • How to move old CDR records to another server?
  • How to migrate PCAP files to a new server?
  • What is the difference between database backup mode and master-master replication?
  • How to migrate GUI settings between servers?
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