This case is possible after the following steps:
1. vmagent successfully performed handshake with the -remoteWrite.url and the remote storage supports zstd-compressed data.
2. remote storage became unavailable or slow to ingest data, vmagent compressed the collected data into blocks with zstd and puts these blocks to persistent queue on disk.
3. vmagent restarts and the remote storage is unavailable during the handshake, then vmagent falls back to Snappy compression.
4. vmagent starts sending zstd-compressed data from persistent queue to the remote storage, while falsely advertizing it sends Snappy-compressed data.
5. The remote storage receives zstd-compressed data and fails unpacking it with Snappy.
The solution is the same as 12cd32fd75, just fall back to zstd decompression if Snappy decompression fails.
This case is possible after the following steps:
1. vmagent tries to perform handshake with the -remoteWrite.url in order to determine whether
the remote storage supports zstd-compressed data.
2. The remote storage is unavailable during the handshake. In this case vmagent falls back to Snappy compression
for the data sent to the remote storage.
3. vmagent compresses the collected data into blocks with Snappy and puts these blocks to persistent queue on disk.
4. The remote storage becomes available.
5. vmagent restarts, performs the handshake with the remote storage and detects that it supports zstd-compressed data.
6. vmagent starts sending Snappy-compressed data from persistent queue to the remote storage,
while falsely advertizing it sends zstd-compressed data.
7. The remote storage receives Snappy-compressed data and fails unpacking it with zstd.
The solution is to just fall back to Snappy decompression if zstd decompression fails.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5301
