[ethereum/go-ethereum] Fatal: out of memory issue (#15428)

@karalabe my eth node is increasing the memory usage like +10mb per hour, the memory used is still growing slowly.

I have run the geth full node without specifying the cache, so it is using the default value (1GB)

Is this a normal behaviour because of the junk accumulated (since the garbage collector will clean up at 2Gb rigth)?