Redundant database: Difference between revisions

From VoIPmonitor.org
(Add PCAP migration section with timezone considerations)
(Rewrite: consolidated structure, removed redundancy, more concise)
 
(7 intermediate revisions by the same user not shown)
Line 1: Line 1:
{{DISPLAYTITLE:Database Replication using a Dedicated Sniffer Instance}}
{{DISPLAYTITLE:Database Redundancy and Migration}}
[[Category:GUI manual]]
[[Category:Configuration]]
[[Category:High Availability]]


This guide explains how to use a dedicated VoIPmonitor sensor instance to perform real-time replication of the CDR database to a secondary MySQL/MariaDB server. This provides a native, application-level method for creating backups or read-only replicas.
This guide covers methods for replicating, synchronizing, and migrating the VoIPmonitor CDR database between instances.


== Overview & Use Case ==
== Overview ==
VoIPmonitor offers a built-in mechanism to replicate its database. This is achieved by running a special instance of the sensor in "database backup mode." In this mode, the sensor does not sniff any packets; its sole purpose is to connect to a primary (source) database, read CDR data, and write it to a secondary (destination) database.


This method is an alternative to traditional MySQL replication and is particularly useful for:
VoIPmonitor offers three methods for CDR synchronization:
* '''Online GUI Migration''': Migrating the GUI database from an old server to a new server with minimal or no downtime. The sensor replicates CDR data incrementally while users continue using the old GUI. Once replication completes, you can switch users to the new GUI without service interruption.
* Creating a read-only replica database for reporting or analysis without impacting the performance of the primary database.
* Setting up a hot-standby database for disaster recovery.
* Consolidating data from multiple, smaller VoIPmonitor databases into one central database.


The process incrementally syncs data starting from a specified date, ensuring that the destination database stays up-to-date in near real-time.
{| class="wikitable"
|-
! 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 [[Mysql_master-master_replication_hints|Master-Master Replication]])
|-
| '''Dual Write''' || Sniffer writes CDRs to two databases simultaneously || Real-time backup, centralized reporting
|}
 
{{Note|All 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 Overview ===
=== Architecture ===


<kroki lang="plantuml">
<kroki lang="plantuml">
Line 21: Line 32:
skinparam shadowing false
skinparam shadowing false
skinparam defaultFontName Arial
skinparam defaultFontName Arial
skinparam rectangle {
  BorderColor #4A90E2
  BackgroundColor #FFFFFF
}


rectangle "OLD Server" as OLD {
rectangle "OLD Server" {
   rectangle "VoIPmonitor\nSniffer" as SNIFF
   rectangle "Sniffer" as SNIFF
   database "MySQL\n(Source DB)" as SRC_DB
   database "Source DB" as SRC
}
}


rectangle "NEW Server" as NEW {
rectangle "NEW Server" {
   rectangle "Migration\nInstance" as MIG
   rectangle "Migration\nInstance" as MIG
   database "MySQL\n(Destination DB)" as DST_DB
   database "Destination DB" as DST
}
}


SNIFF -down-> SRC_DB : writes CDRs
SNIFF -down-> SRC : writes CDRs
MIG -left-> SRC_DB : reads CDRs\n(database_backup_from_*)
MIG -left-> SRC : reads\n(database_backup_from_*)
MIG -down-> DST_DB : writes CDRs\n(mysql*)
MIG -down-> DST : writes\n(mysql*)


note bottom of MIG
note bottom of MIG
   Migration instance runs with:
   No packet capture
  - No packet capture (interface disabled)
   managerport = 5030
   - Different managerport (5030)
  - database_backup_from_date = 2024-01-01
end note
end note
@enduml
@enduml
</kroki>
</kroki>


== Online GUI Migration Workflow ==
=== Online GUI Migration Workflow ===
When migrating the GUI to a new server, you have two primary methods:
 
=== Method 1: Dump/Restore (With Downtime) ===
If a service interruption is acceptable:
# Stop the sniffer on the old server
# Perform a database dump:
#:<syntaxhighlight lang="bash">mysqldump -u root -p voipmonitor > backup.sql</syntaxhighlight>
# Transfer and restore on new server:
#:<syntaxhighlight lang="bash">mysql -u root -p voipmonitor < backup.sql</syntaxhighlight>
# Repoint the GUI to the new database
# Install and configure the new GUI instance
 
This method is simple but requires downtime and may take hours for terabyte-sized databases.


=== Method 2: Online Migration (Minimal/No Downtime) ===
# Install VoIPmonitor GUI on the new server with a fresh database
Using the sensor's database backup mode:
# '''Backup configuration:''' On old GUI → '''Tools → Backup & Restore''' → backup configuration tables
# Install VoIPmonitor GUI on the new server with a fresh empty database
# '''Restore configuration:''' On new GUI → upload the backup file (do this BEFORE starting migration)
# On the old GUI: Go to '''Tools → Backup & Restore → Backup configuration TABLES''' and download the backup file
# Create migration config file (see below)
# On the new GUI: Go to '''Tools → Backup & Restore → Restore configuration tables''' and upload the backup file
# Start migration instance
#:'''IMPORTANT:''' Complete this step BEFORE starting the migration instance
# Create a <code>voipmonitor-migrate.conf</code> file by copying the old <code>voipmonitor.conf</code> and adding migration options (see Configuration section below)
# Configure and run the migration instance in "database backup mode" on the new server
# The sensor connects to the old database and replicates CDR data incrementally
# Once replication catches up, switch users to the new GUI
# Once replication catches up, switch users to the new GUI
# Stop migration instance and decommission the old server
# Stop migration instance and decommission old server
 
For assistance with this method, provide remote SSH access to both the old and new hosts to the support team.
 
== Comparison: Dump/Restore vs Online Migration ==
 
{| class="wikitable"
|-
! Aspect !! Dump/Restore !! Online Migration
|-
| '''Downtime''' || Required (hours for large DBs) || Minimal/None
|-
| '''Complexity''' || Low - Manual SQL dump || Medium - Sensor configuration
|-
| '''Data Loss Risk''' || Moderate (if dump fails) || Low - Incremental sync
|-
| '''Best For''' || Small databases || Large databases, zero-downtime requirements
|}
 
== Configuration ==
To set up database replication, you will run a new, dedicated VoIPmonitor sensor instance on the server that hosts your '''secondary (destination)''' database. This instance requires its own <code>voipmonitor.conf</code> file.
 
=== Creating the Migration Configuration File ===


The migration configuration file should be named consistently to avoid confusion (e.g., <code>voipmonitor-migrate.conf</code>).
=== Configuration ===


'''Important:''' Start with a copy of the existing configuration. The easiest way to create this configuration is to copy the existing <code>voipmonitor.conf</code> from the old server and add the migration-specific options. This ensures all existing settings are preserved.
Copy the original config and modify for migration mode:


<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
# On the NEW server, copy the old config:
scp root@old-server:/etc/voipmonitor.conf /etc/voipmonitor-migrate.conf
scp root@old-server:/etc/voipmonitor.conf /etc/voipmonitor-migrate.conf
</syntaxhighlight>
</syntaxhighlight>


Then edit <code>/etc/voipmonitor-migrate.conf</code> to modify the critical settings for migration mode.
'''Required modifications in <code>/etc/voipmonitor-migrate.conf</code>:'''
 
=== Required Modifications ===
 
If you plan to run the migration instance while the original sniffer continues to capture traffic (zero-downtime migration), you '''MUST''' make the following changes to avoid conflicts:


<syntaxhighlight lang="ini">
<syntaxhighlight lang="ini">
# --- 1. CRITICAL: Change managerport to avoid conflicts ---
# 1. Avoid port conflict with production sniffer
# The original sniffer typically uses managerport = 5029
managerport = 5030
managerport = 5030


# --- 2. CRITICAL: Disable all packet capture bindings ---
# 2. DISABLE packet capture (comment out all interface lines)
# These prevent the migration instance from competing for network interfaces
# interface = eth0
# Comment out or delete ALL interface/bind options:
# interface = eth0       # DISABLE - do not capture packets
# interface = eth1      # DISABLE - do not capture packets
# interface = any        # DISABLE - do not capture packets


# --- 3. Destination Database (where to write data) ---
# 3. Destination Database (NEW server - local)
# Update to point to the NEW server's local database
mysqlhost     = 127.0.0.1
mysqlhost                     = 127.0.0.1
mysqldb       = voipmonitor
mysqldb                       = voipmonitor
mysqlusername = root
mysqlusername                 = root
mysqlpassword = new_password
mysqlpassword                 = new_db_password
cdr_partition                  = yes


# --- 4. Source Database (where to read data from) ---
# 4. Source Database (OLD server - remote)
# These parameters are ADDED to enable replication from the old database
database_backup_from_mysqlhost    = 192.168.0.1
database_backup_from_mysqlhost    = 192.168.0.1
database_backup_from_mysqldb      = voipmonitor
database_backup_from_mysqldb      = voipmonitor
database_backup_from_mysqlusername = root
database_backup_from_mysqlusername = root
database_backup_from_mysqlpassword = old_db_password
database_backup_from_mysqlpassword = old_password


# --- 5. Replication Control ---
# 5. Start date for replication
# Choose the date from which replication should begin
database_backup_from_date = 2024-01-01
database_backup_from_date         = 2024-01-01


# Performance tuning for replication speed
# 6. Performance tuning
database_backup_insert_threads     = 3
database_backup_insert_threads = 3   # Higher = faster but more load
database_backup_pause             = 3
database_backup_pause         = 3   # Higher = less load on source DB
</syntaxhighlight>
</syntaxhighlight>


=== Configuration Parameters Reference ===
'''Parameter Reference:'''


{| class="wikitable"
{| class="wikitable"
Line 155: Line 107:
! Parameter !! Description
! Parameter !! Description
|-
|-
| <code>managerport</code> || TCP port for the sensor's manager API. Must be different from the production sniffer (default: 5029).
| <code>database_backup_from_date</code> || Start date for sync (YYYY-MM-DD)
|-
| <code>interface</code> || Network interface(s) to capture. Must be disabled/commented out for migration instance.
|-
| <code>mysqlhost</code> || IP/hostname of the '''destination''' database (new server).
|-
| <code>database_backup_from_mysqlhost</code> || IP/hostname of the '''source''' database (old server).
|-
|-
| <code>database_backup_from_date</code> || Start date for incremental sync (format: YYYY-MM-DD).
| <code>database_backup_insert_threads</code> || Parallel write threads (higher = faster, more load)
|-
|-
| <code>database_backup_insert_threads</code> || Number of parallel threads for inserting data (default: 1).
| <code>database_backup_pause</code> || Seconds between batches (higher = gentler on source DB)
|-
|-
| <code>database_backup_pause</code> || Pause in seconds between sync batches (default: 0).
| <code>database_backup_desc_dir</code> || Set <code>yes</code> to also write new incoming data to destination
|}
|}


=== Why These Changes Are Required ===
=== Running the Migration ===
 
;'''managerport'''
:VoIPmonitor uses this port for internal communication and GUI connectivity. If both instances use the same port, they will conflict.
 
;'''interface options'''
:The migration instance should NOT capture packets - its only purpose is database replication. Disabling packet capture prevents:
:* CPU competition with the production sniffer
:* Duplicate packets being processed by both instances
:* Network interface conflicts
 
=== GUI Configuration Backup ===
 
Before starting the migration instance, you must migrate the GUI configuration tables (users, sensors, capture rules, alerts). This is done via the GUI's '''Tools → Backup & Restore''' feature.
 
'''IMPORTANT:''' Complete this step BEFORE starting the migration instance. See [[Backup_and_restore_GUI_tables|Backup and restore GUI tables]] for detailed instructions.
 
== Running the Replication Instance ==
 
Once your configuration file is ready, you can start the sensor in this special mode.
 
=== Manual Test Run ===
It is highly recommended to first run the process manually to ensure all settings are correct and there are no connection errors.


'''Test manually first:'''
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
voipmonitor --config-file /etc/voipmonitor-migrate.conf -k -v 1
voipmonitor --config-file /etc/voipmonitor-migrate.conf -k -v 1
</syntaxhighlight>
</syntaxhighlight>


;Command-line options:
'''Run as systemd service:'''
* <code>-k</code>: Prevents the process from forking into the background (keeps it in foreground).
* <code>-v 1</code>: Sets verbosity to level 1, which will show status information.
 
Watch the output for any database connection errors or other warnings. A successful start will show messages indicating CDR data is being read from the source and written to the destination.
 
=== Running as a Service ===
To run the migration instance permanently as a background service, you will need to create a separate <code>systemd</code> or <code>init.d</code> service file for it. This process is covered in the [[Multiple_sniffer_instancies|Multiple Sniffer Instances]] guide. The key is to ensure the new service unit file uses the <code>-c /etc/voipmonitor-migrate.conf</code> argument to load your specific configuration.
 
Example <code>systemd</code> unit file (<code>/etc/systemd/system/voipmonitor-migrate.service</code>):


Create <code>/etc/systemd/system/voipmonitor-migrate.service</code>:
<syntaxhighlight lang="ini">
<syntaxhighlight lang="ini">
[Unit]
[Unit]
Description=VoIPmonitor Database Migration Instance
Description=VoIPmonitor Database Migration
After=network.target mysql.service
After=network.target mysql.service


Line 223: Line 140:
</syntaxhighlight>
</syntaxhighlight>


Enable and start:
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
systemctl daemon-reload
systemctl daemon-reload
systemctl enable voipmonitor-migrate
systemctl enable --now voipmonitor-migrate
systemctl start voipmonitor-migrate
</syntaxhighlight>
</syntaxhighlight>


== Migrating PCAP (Packet Capture) Files ==
== Dual Write Method ==
The database migration process described above migrates only the '''CDR (Call Detail Records)'''. It does not migrate PCAP files. You must migrate PCAP files separately.
 
Configure the sniffer to write each CDR to both local and remote databases simultaneously.
 
=== Configuration ===


=== Using rsync to Copy PCAPs ===
Add secondary database parameters to <code>/etc/voipmonitor.conf</code>:


Use <code>rsync</code> over SSH to copy the <code>spooldir</code> (default: <code>/var/spool/voipmonitor</code>) from the old server to the new server.
<syntaxhighlight lang="ini">
# Primary Database (local)
mysqlhost      = 127.0.0.1
mysqldb        = voipmonitor
mysqlusername  = root
mysqlpassword  = primary_password


<syntaxhighlight lang="bash">
# Secondary Database (remote) - enables dual write
# Run on NEW SERVER pulling from OLD
mysql2host      = 192.168.1.100
rsync -avz root@old-server:/var/spool/voipmonitor/ /var/spool/voipmonitor/
mysql2db        = voipmonitor
mysql2username  = root
mysql2password  = secondary_password
</syntaxhighlight>
</syntaxhighlight>


;<code>-a</code>: Archive mode (preserves permissions, times, symbolic links)
{{Warning|1=If the secondary database becomes unreachable, CDRs are written only to primary. Missed CDRs are NOT retroactively synced.}}
;<code>-v</code>: Verbose output
;<code>-z</code>: Compress during transfer (saves bandwidth)


=== Timezone Considerations (CRITICAL) ===
=== Comparison: Dual Write vs Master-Master ===


;'''OS Timezone Must Match'''
{| class="wikitable"
:If you are copying PCAP files from an old probe to a new probe that will continue capturing, ensure both systems have the <strong>same OS timezone</strong> configured.
|-
! Aspect !! Dual Write !! Master-Master
|-
| '''Complexity''' || Low (add mysql2* params) || Medium (MySQL replication setup)
|-
| '''Bidirectional''' || No || Yes
|-
| '''GUI Settings Sync''' || No || Yes
|-
| '''Best For''' || Simple one-way backup || Full HA setup
|}


PCAP file paths are based on directory structure: <code>spooldir/YYYY-MM-DD/HH/MM/</code>. The directory structure uses the system's local timezone. If the old probe was in timezone A and the new probe is in timezone B, the new probe will create PCAP files in different directory paths than the old files. This can cause the GUI to fail to find or link historical PCAPs.
== Migrating PCAP Files ==


The database stores relative paths, so as long as the directory structure is preserved and the timezone remains the same, the GUI will correctly reference the old PCAPs.
Database migration does NOT include PCAP files. Migrate separately using rsync:


To check/set timezone:
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
# Check current timezone
rsync -avz root@old-server:/var/spool/voipmonitor/ /var/spool/voipmonitor/
</syntaxhighlight>
 
{{Warning|1='''Timezone must match between servers.''' PCAP paths use local timezone (<code>spooldir/YYYY-MM-DD/HH/MM/</code>). Mismatched timezones cause GUI to fail finding historical PCAPs.}}
 
<syntaxhighlight lang="bash">
# Check timezone
timedatectl
timedatectl


# Set timezone (example for Europe/Prague)
# Set timezone
timedatectl set-timezone Europe/Prague
timedatectl set-timezone Europe/Prague
</syntaxhighlight>
</syntaxhighlight>


=== Architecture-Specific Considerations ===
== 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


;'''Client-Server Mode with Local Processing'''
'''To identify schema changes manually:'''
:In the new architecture where probes store their own PCAPs (<code>packetbuffer_sender=no</code>), you have these options:
<syntaxhighlight lang="bash">
:* Keep the PCAPs on the OLD probe hardware if it is becoming one of the new probes
systemctl restart voipmonitor
:* Archive historical PCAPs to external storage
tail -f /var/log/voipmonitor/voipmonitor.log | grep -E "CLI|ALTER|CREATE TABLE"
:* Copy to the new probe '''only if timezone matches'''
</syntaxhighlight>


;'''Centralized PCAP Storage'''
{{Warning|1=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.}}
:If you are centralizing PCAPs (<code>packetbuffer_sender=yes</code>), copy all old PCAPs to the Central Server's spool directory. Ensure the central server's OS timezone matches all probes' timezones.
 
== See Also ==
 
* [[Mysql_master-master_replication_hints|Master-Master Replication]]
* [[Backing_Up_GUI_Configuration|Backing Up GUI Configuration]]
* [[Multiple_sniffer_instancies|Multiple Sniffer Instances]]


== AI Summary for RAG ==
== AI Summary for RAG ==
'''Summary:''' This article describes how to use a dedicated VoIPmonitor sensor instance in "database backup mode" to perform application-level replication of the MySQL/MariaDB database. This is useful for online GUI migration with minimal downtime, creating read-only replicas, hot-standby backups, or disaster recovery. The configuration requires setting up destination database parameters (mysqlhost, etc.) and source database parameters (database_backup_from_mysqlhost, etc.), with database_backup_from_date controlling the sync starting point. PCAP files must be migrated separately using rsync, with critical attention to timezone matching between old and new servers to ensure PCAP files remain accessible through the GUI.


'''Keywords:''' database replication, backup, mysql backup, mariadb replication, replica, read-only, standby, disaster recovery, GUI migration, migrate database, online migration, zero downtime, database_backup_from_date, database_backup_from_mysqlhost, voipmonitor.conf, high availability, PCAP migration, spooldir, rsync, timezone, packetbuffer_sender, client-server mode, centralized storage
'''Summary:''' VoIPmonitor offers three CDR synchronization methods: (1) Database Backup Mode - a dedicated sensor reads from source DB and writes to destination DB for online migration or read-only replicas, configured with <code>database_backup_from_*</code> parameters; (2) Master-Master Replication - bidirectional MySQL replication for full HA (see separate article); (3) Dual Write - sniffer writes CDRs to both local and remote DB using <code>mysql2*</code> parameters. Key configuration: <code>database_backup_from_date</code> sets sync start date, <code>database_backup_pause</code> controls load on source DB (higher = less load), <code>database_backup_insert_threads</code> controls write parallelism. Migration instance must disable packet capture (comment out <code>interface</code>) and use different <code>managerport</code>. PCAP files must be migrated separately with rsync, ensuring timezone matches between servers. The migration instance automatically handles database schema upgrades when moving between MySQL/MariaDB versions.
 
'''Keywords:''' database replication, mysql backup, database migration, online migration, zero downtime, database_backup_from_date, database_backup_from_mysqlhost, database_backup_pause, database_backup_insert_threads, dual write, mysql2host, PCAP migration, rsync, timezone, schema upgrade, voipmonitor-migrate.conf, read-only replica, disaster recovery, high availability


'''Key Questions:'''
'''Key Questions:'''
* How can I migrate the GUI database with minimal downtime?
* How can I migrate VoIPmonitor database with zero downtime?
* What is the difference between dump/restore and online migration?
* What methods are available for database replication in VoIPmonitor?
* How can I create a real-time backup of my VoIPmonitor database?
* What is the difference between database backup mode, dual write, and master-master replication?
* How do I replicate the VoIPmonitor database to another server?
* How do I configure the migration instance (voipmonitor-migrate.conf)?
* What is the "database backup mode" for the sniffer?
* How can I control database load during replication (database_backup_pause)?
* What configuration is needed to mirror the VoIPmonitor database?
* How do I configure dual write mode (mysql2* parameters)?
* Can I use VoIPmonitor to create a read-only replica for reporting?
* How does database_backup_from_date work?
* How do I migrate PCAP files to a new server?
* How do I migrate PCAP files to a new server?
* Why is timezone matching important when migrating PCAP files?
* Why is timezone matching important when migrating PCAP files?
* How can I use rsync to copy VoIPmonitor spooldir?
* Does the migration instance handle database schema upgrades automatically?
* What configuration parameters are needed for database backup mode?

Latest revision as of 16:48, 8 January 2026


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

Overview

VoIPmonitor offers three 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)
Dual Write Sniffer writes CDRs to two databases simultaneously Real-time backup, centralized reporting

ℹ️ Note: All 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. Performance tuning
database_backup_insert_threads = 3   # Higher = faster but more load
database_backup_pause          = 3   # Higher = less load on source DB

Parameter Reference:

Parameter Description
database_backup_from_date Start date for sync (YYYY-MM-DD)
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 to also write new incoming data to destination

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

Dual Write Method

Configure the sniffer to write each CDR to both local and remote databases simultaneously.

Configuration

Add secondary database parameters to /etc/voipmonitor.conf: 

# Primary Database (local)
mysqlhost      = 127.0.0.1
mysqldb        = voipmonitor
mysqlusername  = root
mysqlpassword  = primary_password

# Secondary Database (remote) - enables dual write
mysql2host      = 192.168.1.100
mysql2db        = voipmonitor
mysql2username  = root
mysql2password  = secondary_password

⚠️ Warning: If the secondary database becomes unreachable, CDRs are written only to primary. Missed CDRs are NOT retroactively synced.

Comparison: Dual Write vs Master-Master

Aspect Dual Write Master-Master
Complexity Low (add mysql2* params) Medium (MySQL replication setup)
Bidirectional No Yes
GUI Settings Sync No Yes
Best For Simple one-way backup Full HA setup

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 offers three CDR synchronization methods: (1) Database Backup Mode - a dedicated sensor reads from source DB and writes to destination DB for online migration or read-only replicas, configured with database_backup_from_* parameters; (2) Master-Master Replication - bidirectional MySQL replication for full HA (see separate article); (3) Dual Write - sniffer writes CDRs to both local and remote DB using mysql2* parameters. Key configuration: database_backup_from_date sets sync start date, database_backup_pause controls load on source DB (higher = less load), database_backup_insert_threads controls write parallelism. Migration instance must disable packet capture (comment out interface) and use different managerport. PCAP files must be migrated separately with rsync, ensuring timezone matches between servers. The migration instance automatically handles database schema upgrades when moving between MySQL/MariaDB versions.

Keywords: database replication, mysql backup, database migration, online migration, zero downtime, database_backup_from_date, database_backup_from_mysqlhost, database_backup_pause, database_backup_insert_threads, dual write, mysql2host, PCAP migration, rsync, timezone, schema upgrade, voipmonitor-migrate.conf, read-only replica, disaster recovery, high availability

Key Questions:

  • How can I migrate VoIPmonitor database with zero downtime?
  • What methods are available for database replication in VoIPmonitor?
  • What is the difference between database backup mode, dual write, and master-master replication?
  • How do I configure the migration instance (voipmonitor-migrate.conf)?
  • How can I control database load during replication (database_backup_pause)?
  • How do I configure dual write mode (mysql2* parameters)?
  • How do I migrate PCAP files to a new server?
  • Why is timezone matching important when migrating PCAP files?
  • Does the migration instance handle database schema upgrades automatically?
  • What configuration parameters are needed for database backup mode?
Retrieved from "https://www.voipmonitor.org/doc/index.php?title=Redundant_database&oldid=10096"