Comment 1 for bug 1801364

Example data for the case that triggered this issue:

From debug output inserted into util.load_json, which is called from read_v2() in openstack.py

"random_seed": "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"

After processing this turned into:

u'random_seed': '\xb8!\')\xe0\x0e%<\xac)E\xf6\xe0.kt>V0\x88\xdf\xb0\x02:\xbc\x192F+)P5\x9eL\xab\xbd\xf5\xa2g7\x02J\xfb\xd6\x14>^\xe9\x87\xf1\xa1LJ\xd1\xbc\xe3y\x0b\xd73\x93\xc3\xb8%3\xac_\x1cN\x02F\xf3\xec\xdaA.^\x7f\x1e\xf2\x958\x7f\xc8_f\x0c\xf3\x9e\xce\xb3\xe7>\xfa\x9a\xe6\xbbX/\x01>\r\xc8\xa1\xb1\x852\x05@:\xbb\xa3\x98\xa1\xf7\x11\x82\xbeCN\xe9.\xd7\xa6\x85\xf9\x0b\t\xa7\xcd\xc3U\'\xac\xaa\xc2\xea\r\x11\xe1\xdc\'\x0c\x9a\x7f\x85\xcc\xe3\xac]4S\xad\x08V\xcc\xba\xf6\xf2\x89\xc40\xad\xfc%\xab?\tP\xc9\x82\x87}z\x91\xd6\x94\x17\x8e\x83\xa3\x15\xc5\xfc\x01\x81E\xc0w|\x98Q4=\x9f\x07\xf1\xa3ot\xc6\x87X\xd0\xe1\x93\xae\xbe\x0f\\\xd3\x08VU\x1d\xf8H\xbb\xa4/\xc1\x96\x83\xb7\xed\x89\xb7\xa2\x10O\x1c*\xc4\xbc\xf6*2\x9cq\x9c\x10\xd8q\x93\xec\xd2\x0e\xd3\xb3\xed\xa2\xf8\x8b\xcb1VT\x9f 4\xdeg;\xf5\xe3\xdb\xd9\xb7\xe7\x90\xf3@\xf4qn\xcf\xf0x\xed*X`\x13YS\x12\xa6&\xfe\xb5)/\xf5|\x8bp\t\xc6\xfb3\x03/\xaf\xefa\x1b+\xa2F7\x10\x18\x91?&\xe8\x88\x1bY~%|\xb1\xe8\x1c\x96\xdf\xa1\xabH\xf7\xab\xb8\xc7\xdfgT#\xf2\xbd\x198j%\xba\x1f\xea\x96\x1e\r_\xaeRe)\xb5"-\xbf\xe7\xb9\x8c\xdb$\xf2{\x98\x04o\xd7D\x86\xce\x86\xf7F\xa4\x8e:OZv@K0\x0c\x0e\xf4\xf6\xce\x9c\xc8\x8ai\xa1\xf1Ec\x95U\x88.\xc1\xce\xb5\x92\x98\xb5\xe7\xf3\xc4\xd5\xc2\x1fR\xe5`-\xbd\xeaBC\xc0\xad\xdda\xb0oX\xf2b\xf88a\x12\x94R^\x0812\x7f\xa2v\x06Q\xc8\x13X\x8e\x8d-\x82\x1b\x82\x17\x18\x1c\xdd>\x8c\x13\x190\\"z\x8f\xa6\x18\xf3\xbf\x9e\x95\xa7\x8d\x89\x91\x83\x1a\xe5\xbe\xcfK\x08\xff[!\xe5\xba\x9f\xfah~\x85\x16\x18\xd9GX\x9f\x0c\xa4\xa9\xb7\xdcn\xd2\xaf5\xc6\xbc', u'uuid': u'4f9baeab-1f8c-48ca-8766-37c4c59927cf'

per debug output inserted into _crawl_metadata(). With this data in the metadata dictionary persisting the data via persist_instance_data() fails with the message shown in the description.

The question is whether "random_seed" should be persisted in the first place. The value for "random_seed" is different every time the metadata server is accessed. Thus the value is not useful for comparison. However I do not know for what other reasons the persisted data would be used.