Documentation Index
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The C++ IOCP GameServer reads two runtime configuration files — Database.ini and Redis.ini — before opening its listen socket. Everything else that shapes server behavior is baked into Common/Config.h as constexpr values and takes effect only after a recompilation. This page documents both layers so you can tune the server for your environment without hunting through header files.
Database.ini
Copy Database.example.ini to Database.ini in the same directory as the server binary and fill in your MySQL/MariaDB credentials. The file is excluded from source control by .gitignore.
| Field | Type | Default | Description |
|---|
host | string | 127.0.0.1 | Hostname or IP address of the MySQL/MariaDB server |
port | integer | 3306 | TCP port the database listens on |
user | string | game | Database user the server authenticates as |
password | string | game_password | Password for the database user |
database | string | game | Schema/database name to connect to |
allow_dev_fallback | bool | true | When true, a hardcoded test / 1234 credential pair remains valid even if the database is unreachable. Set to false in any environment beyond local development. |
# Database.ini
host=127.0.0.1
port=3306
user=game
password=s3cur3_g@me_pass
database=game
allow_dev_fallback=false
Redis.ini
Copy Redis.example.ini to Redis.ini in the same directory as the server binary.
| Field | Type | Default | Description |
|---|
host | string | 127.0.0.1 | Hostname or IP address of the Redis server |
port | integer | 6379 | TCP port Redis listens on |
password | string | (empty) | AUTH password; leave blank if Redis has no password set |
database | integer | 0 | Redis logical database index (0–15) |
allow_dev_fallback | bool | false | When true, Redis connectivity failures are tolerated during development. Keep false in production. |
# Redis.ini
host=127.0.0.1
port=6379
password=r3d1s_s3cr3t
database=0
allow_dev_fallback=false
Compile-time constants (Config.h)
All values below live in the Config namespace inside ServerSolution/Common/Config.h. Changing any of them requires a full rebuild of the server binary.
These constants are evaluated at compile time. Modifying Config.h without recompiling the project has no effect on a running or previously built binary.
Network
| Constant | Value | Description |
|---|
ListenPort | 7777 | TCP port the server accepts gameplay connections on |
UdpListenPort | 7777 | UDP port used for low-latency movement datagrams |
Backlog | 2147483647 (0x7fffffff) | listen() backlog passed to the OS |
BufferSize | 4096 | Default I/O buffer size per operation (bytes) |
MaxPacketSize | 16384 | Maximum allowed size of a single received packet (16 × 1024 bytes) |
MaxEchoPayloadSize | 4096 | Maximum payload size for echo packets (4 × 1024 bytes) |
RecvBufferSize | 131072 | Per-session receive ring-buffer size (128 × 1024 bytes) |
SendBufferSize | 65536 | Per-session send buffer size (64 × 1024 bytes) |
InitialSessionPoolSize | 1024 | Number of session objects pre-allocated in the pool at startup |
InitialSendPacketBufferPoolSize | 1024 | Number of send-packet buffer objects pre-allocated in the pool |
InitialRecvBufferBlockPoolSize | 1024 | Number of receive-buffer block objects pre-allocated in the pool |
WORKER_THREAD_COUNT | 4 | Number of IOCP worker threads servicing completion packets |
MAX_CONCURRENT_THREADS | 0 | IOCP concurrency hint passed to CreateIoCompletionPort; 0 means use the CPU core count |
| Constant | Value | Description |
|---|
MinLoginAccountLength | 4 | Minimum number of characters in an account name |
MaxLoginAccountLength | 64 | Maximum number of characters in an account name |
MinLoginPasswordLength | 8 | Minimum number of characters in a password |
MaxLoginPasswordLength | 128 | Maximum number of characters in a password |
MaxChatMessageLength | 512 | Maximum character length of a single chat message payload |
Session and threading
| Constant | Value | Description |
|---|
MaxPacketsPerSecond | 100 | Per-session inbound packet rate limit; excess packets are dropped |
MaxSessionJobQueueSize | 1024 | Maximum number of jobs queued per session before backpressure is applied |
SessionJobWorkerCount | 4 | Number of worker threads processing per-session job queues |
HeartbeatIntervalSeconds | 5 | How often the server expects a heartbeat from each client (seconds) |
HeartbeatTimeoutSeconds | 15 | Seconds without a heartbeat before a session is forcibly closed |
Inventory persistence
| Constant | Value | Description |
|---|
InventoryDbWorkerCount | 2 | Number of worker threads dedicated to inventory database writes |
MaxInventoryDbQueueSize | 4096 | Maximum number of inventory write operations queued before backpressure |
Character-state persistence
| Constant | Value | Description |
|---|
CharacterStateSaveBucketIntervalSeconds | 1.0 | Duration of each save bucket in seconds; total save cycle = BucketCount × BucketInterval (10 s) |
CharacterStateSaveBucketCount | 10 | Number of time-slice buckets that spread dirty-character flushes across the save interval |
CharacterStateDbBatchSize | 100 | Maximum number of character rows written to the database in a single batch flush |
CharacterStateDbRetryCount | 2 | Number of times a failed character-state batch write is retried before the error is logged and dropped |
Game simulation
| Constant | Value | Description |
|---|
GameSimulationTickIntervalMs | 33 | Simulation tick period in milliseconds (~30 Hz) |
MaxGameSimulationCommandQueueSize | 65536 | Maximum number of pending simulation commands buffered (64 × 1024) before backpressure is applied |
Movement and AoI
| Constant | Value | Description |
|---|
MaxMovementDeltaSeconds | 0.05 | Maximum time-delta accepted for a single movement step; larger deltas are clamped |
MovementAoiViewDistance | 3000.0 | Area-of-Interest radius for broadcasting movement updates (Unreal units) |
MovementAoiCellSize | 3000.0 | AoI spatial-hash cell size; equals MovementAoiViewDistance |
MovementNotifyIntervalMs | 100 | Minimum interval between movement-notification dispatches per entity (ms) |
MovementNotifyDatagramBytes | 1200 | Maximum UDP datagram size used for movement replication packets (bytes) |
MaxMovementReplicationPendingSnapshots | 65536 | Maximum number of pending movement snapshots queued for replication (64 × 1024) |
MovementMaxWalkSpeed | 500.0 | Maximum authoritative walk speed used in server-side movement validation (Unreal units/s) |
MovementMaxAcceleration | 800.0 | Maximum authoritative acceleration (Unreal units/s²) |
MovementBrakingDecelerationWalking | 750.0 | Authoritative braking deceleration while walking (Unreal units/s²) |
MovementGroundFriction | 5.0 | Ground-friction coefficient used in server-side movement integration |
MovementBrakingFrictionFactor | 1.0 | Multiplier applied to friction during braking |
MovementMinAnalogWalkSpeed | 150.0 | Minimum speed threshold for analog (stick) movement (Unreal units/s) |
MovementInputDeadZone | 0.01 | Input magnitude below this threshold is treated as zero |
MovementInputTimeoutMs | 250 | Milliseconds after which a movement input is considered stale and discarded |
Monster AI
| Constant | Value | Description |
|---|
MonsterAoiViewDistance | 3000.0 | AoI radius for monster aggro and visibility; equals MovementAoiViewDistance |
MonsterAoiRefreshIntervalSeconds | 0.2 | How often the monster AoI grid is re-queried (seconds) |
MonsterRespawnDelaySeconds | 30 | Seconds after death before a monster re-spawns |
Combat and load testing
| Constant | Value | Description |
|---|
EnableCombatDebugPackets | true | Send additional debug packets during combat for client-side diagnostics |
EnableLoadTestSpawnSpread | true | Distribute load-test entities across a grid instead of spawning them at a single point |
LoadTestSpawnSpacing | 4000.0 | Grid spacing between load-test entities (Unreal units; equals MovementAoiViewDistance + 1000) |
LoadTestSpawnGridWidth | 10 | Number of columns in the load-test spawn grid |
Logging
| Constant | Value | Description |
|---|
LogAsyncQueueSize | 32768 | Capacity of the async log queue in entries (32 × 1024) |
LogWriterThreadCount | 1 | Number of background threads consuming the async log queue |
LogMaxFileSizeBytes | 52428800 | Maximum size of a single log file before rotation (50 × 1024 × 1024 bytes) |
LogMaxFiles | 10 | Maximum number of rotated log files retained on disk |
Metrics
| Constant | Value | Description |
|---|
EnablePerfMetrics | true | Master switch for the performance metrics subsystem |
EnablePerfConsoleLog | false | Print performance metrics to stdout on each interval tick |
EnablePerfCsvLog | true | Write rolling performance metrics to Logs/perf_metrics.csv |
PerfLogIntervalSeconds | 5 | How often a metrics snapshot is recorded (seconds) |
PerfCsvLogPath | "Logs/perf_metrics.csv" | Relative path of the CSV metrics output file |
EnablePrometheusEndpoint | true | Expose a Prometheus /metrics HTTP endpoint |
PrometheusHttpPort | 9108 | Port the embedded Prometheus HTTP listener binds to |
Port summary
| Port | Protocol | Purpose |
|---|
7777 | TCP | Client gameplay connections (IOCP session layer) |
7777 | UDP | Low-latency movement datagram channel |
9108 | HTTP (TCP) | Prometheus /metrics scrape endpoint |