handleMessage returns bool to signal session end instead of calling
osExit directly. Defers (pool stop, writeCh close, writerWg wait)
now run before exit, preventing in-flight result loss and panics
from writes to closed channels.
Fix 1: Limit inbound job payload size to 4MB to prevent OOM from malicious server
Fix 2: Worker pool submit accepts context and returns bool, prevents blocking event loop
Fix 3: Panic recovery in worker pool goroutines prevents permanent worker death
Fix 4: WebSocket handshake timeout (30s) prevents indefinite blocking on slow server
Fix 5: Writer goroutine propagates errors to main loop via writeErrCh
Use sync.Pool to reuse 4KB byte slices for protobuf marshaling via
MarshalAppend instead of allocating fresh buffers per result message.
Reduces GC pressure under high-throughput polling.
Accumulate SNMP results and flush in batches of 50 or every 100ms,
whichever comes first. Reduces per-message overhead when thousands
of devices produce results near-simultaneously. Also flushes
remaining results on disconnect/shutdown.
Raise write channel from 500 to 10000, SNMP/monitoring result
channels from 1000 to 10000, MikroTik/credential channels to 5000.
Prevents silent data loss when polling thousands of devices.
Replace unbounded goroutine spawning with fixed-size worker pools:
100 workers for SNMP, 20 for MikroTik, 50 for ping. Prevents file
descriptor exhaustion and device overload when handling thousands
of concurrent jobs. Pool provides backpressure when saturated.
Use strconv.FormatInt/FormatUint instead of fmt.Sprintf for integer
conversions in snmpValueToString. Use encoding/hex + strings.Builder
instead of fmt.Sprintf loop in formatHex. Use strconv.FormatUint for
WebSocket ref counter. Reduces allocations per OID significantly.
