add support for resp3 #182
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- add new command line argument, '--resp', to send HELLO command
at the begining of a connection to set the RESP mode: 2 or 3.
- the redis protocol component updated to support the new RESP 3 types.
exceptional are:
- Push type: Maybe will be added on next phase, but need to understand better
how and what does it mean to benchmark Redis with push commands.
- Streamed strings & Streamed aggregated: Currently not used by Redis.
- remove unused set_authentication() & set_select_db() - unite all the setup state enums of aute, db selection, cluster slots and the new hello to one setup_state enum, as all of them have the same states of none, sent and done.
memtier_benchmark.cpp
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| { "port", 1, 0, 'p' }, | ||
| { "unix-socket", 1, 0, 'S' }, | ||
| { "protocol", 1, 0, 'P' }, | ||
| { "resp", 1, 0, o_resp }, |
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Did you consider extending --protocol instead of adding another flag?
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Yes, but for me, it seems more internal configuration under the Redis protocol. and for backport compatibility, we probably need to add another 2 options (redis-resp2, redis-resp3) as the existing one refers to not set resp version at all.
protocol.cpp
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| if (conf == PROTOCOL_CONF_RESP2 || conf == PROTOCOL_CONF_RESP3) { | ||
| m_resp3 = conf == PROTOCOL_CONF_RESP3; | ||
| size = evbuffer_add_printf(m_write_buf, |
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Do we want to maintain a backwards compatible mode where we don't send HELLO and we assume we're using RESP2? Without it, we'd lose compatibility with Redis <6.0.
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Not sure I got it. In the current implementation if the user doesn't add --resp he will get the old behavior (will not get into this piece of code).
| return size; | ||
| } | ||
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| bool redis_protocol::aggregate_type(char c) { |
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I wonder if these additional branches are going to have some measurable impact on performance, being executed in tight loops. If that's the case, maybe we'd want to subclass redis_protocol into V2 and V3 instead.
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Well not sore it is noticeable and that simple benchmark (of memtier-benchmark) will show us something.
regarding your suggestion to subclass it, do you mean that V2 will not have the impact on the performance as V3?
@filipecosta90 WDYT about this performance concern?
- change config->protocol to be one of the PROTOCOL_TYPE enum (instead of char *) - use --protocol to set resp2 or resp3 instead of --resp
at the begining of a connection to set the RESP mode: 2 or 3.
exceptional are:
how and what does it mean to benchmark Redis with push commands.