Why are my text files sometimes empty when I make a read to them?

My implementation:

I have a script Caller.sh that runs in the background that continuously calls the following scripts:

createtext.sh
createtext2.sh
createtext3.sh

Each of these scripts does the following (but with different text file names):

#! /bin/bash

LogFiletmp="getinfotmp.txt"
LogFile="getinfo.txt"

ssh admin@localhost "show all" > $LogFiletmp         #this output is redirect to a temp file
mv $LogFiletmp $LogFile

I have other scripts that read getinfo.txt, but at times, the text file is empty for up to a couple seconds...Does anybody know why? getinfo.txt should always have something in it and the mv command should work pretty fast right?

ssh admin@localhost "show all" >> $LogFiletmp 

>> means append the output

> means empty the file, then export the output.