// Allocate regions larger than pool buffer size to force new allocations
        RdmaMemoryRegion region1 = bufferManager.getSendRegion(131072); // 128KB > 64KB pool size
        RdmaMemoryRegion region2 = bufferManager.getSendRegion(131072); // Another large allocation

        assertTrue(bufferManager.getTotalAllocated() > initialAllocated, "Total allocated should increase");

     *
     * @param minSize minimum required size
     * @return memory region for sending
     * @throws IOException if allocation fails
     */
    public RdmaMemoryRegion getSendRegion(int minSize) throws IOException {
        if (minSize <= sendBufferSize) {
            RdmaMemoryRegion region = availableSendRegions.poll();
            if (region != null) {
                region.getBuffer().clear();