[libvirt] increase number of libvirt threads by starting tansient guest doamin - is it a bug?

hello, if i start a transient guest doamin via "virsh create abcd.xml" i see an additional libvirt thread and also some open files: pstree -h `pgrep libvirtd` libvirtd───11*[{libvirtd}] libvirtd 3016 root 21w REG 253,0 6044 1052094 /var/log/libvirt/libxl/abcd.log libvirtd 3016 root 22r FIFO 0,8 0t0 126124 pipe libvirtd 3016 root 23w FIFO 0,8 0t0 126124 pipe libvirtd 3016 root 24u REG 0,37 0 4 /proc/xen/privcmd libvirtd 3016 root 25u unix 0xffff8807d2c3ad80 0t0 126125 socket libvirtd 3016 root 26r FIFO 0,8 0t0 126127 pipe libvirtd 3016 root 27w FIFO 0,8 0t0 126127 pipe libvirtd 3016 root 28r FIFO 0,8 0t0 124783 pipe libvirtd 3016 root 29w FIFO 0,8 0t0 124783 pipe libvirtd 3016 root 30r FIFO 0,8 0t0 127140 pipe libvirtd 3016 root 31w FIFO 0,8 0t0 127140 pipe if i destroy these vm via "virsh destroy abcd", i see that the additional thread still exists and also the list of openfiles is the same. if i start the transient guest domain again, i observe an increase in the number of libvirt threads ans also in the list of openfiles: [root@localhost libxl]# pstree -h `pgrep libvirtd` libvirtd───12*[{libvirtd}] libvirtd 3016 root 21w REG 253,0 13783 1052094 /var/log/libvirt/libxl/abcd.log libvirtd 3016 root 22r FIFO 0,8 0t0 126124 pipe libvirtd 3016 root 23w FIFO 0,8 0t0 126124 pipe libvirtd 3016 root 24u REG 0,37 0 4 /proc/xen/privcmd libvirtd 3016 root 25u unix 0xffff8807d2c3ad80 0t0 126125 socket libvirtd 3016 root 26r FIFO 0,8 0t0 126127 pipe libvirtd 3016 root 27w FIFO 0,8 0t0 126127 pipe libvirtd 3016 root 28r FIFO 0,8 0t0 124783 pipe libvirtd 3016 root 29w FIFO 0,8 0t0 124783 pipe libvirtd 3016 root 30r FIFO 0,8 0t0 127140 pipe libvirtd 3016 root 31w FIFO 0,8 0t0 127140 pipe libvirtd 3016 root 32w REG 253,0 13783 1052094 /var/log/libvirt/libxl/abcd.log libvirtd 3016 root 33r FIFO 0,8 0t0 129039 pipe libvirtd 3016 root 34w FIFO 0,8 0t0 129039 pipe libvirtd 3016 root 35u REG 0,37 0 4 /proc/xen/privcmd libvirtd 3016 root 36u unix 0xffff8807d398bb80 0t0 129040 socket libvirtd 3016 root 37r FIFO 0,8 0t0 129042 pipe libvirtd 3016 root 38w FIFO 0,8 0t0 129042 pipe libvirtd 3016 root 39r FIFO 0,8 0t0 129043 pipe libvirtd 3016 root 40w FIFO 0,8 0t0 129043 pipe libvirtd 3016 root 41r FIFO 0,8 0t0 129044 pipe libvirtd 3016 root 42w FIFO 0,8 0t0 129044 pipe if i destroy the doamin again and define them via "virsh define abcd.xml" and start them then via "virsh start abcd", the number of libvirtd threads don´t increase again and also the number of open files is the same. My question: is it normal that for transient guest domains the created libvirtd thread sill exists and also the open files after i destroy the doamin? or is it bug? thanks max