> [!WalSenderWriteData] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_client_walsenderwritedata.png"></td><td><b>Wait Category</b></td><td>Client</td></tr><tr><td><b>Mechanism</b></td><td><code>WalSenderMain</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Distributed/Redistribute">Redistribute</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/Network">Network</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3"><b>Network Congestion Bottleneck</b>. The database has already successfully read the WAL data from disk and is prepared to stream it to the replica, but the operating system's network buffer is currently full.</td></tr></table>