metric: Add memdb size and key count metric #495
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Signed-off-by: longfangsong <longfangsong@icloud.com>
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| @@ -358,6 +361,7 @@ func (db *MemDB) setValue(x memdbNodeAddr, value []byte) { | |||
| } | |||
| x.vptr = db.vlog.appendValue(x.addr, x.vptr, value) | |||
| db.size = db.size - len(oldVal) + len(value) | |||
| metrics.MemdbSize.Set(float64(db.size)) | |||
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Should Add be used for the MemdbSize as it's a server metric?
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There could be multiple |
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I see, it's for measuring the actual memory consumed by memdb. We can run some experiments with large transactions and compare our metrics with the profiling results to see if it's accurate. |
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We don't have a clear idea of the relationship between |
| @@ -563,6 +567,8 @@ func (db *MemDB) deleteNode(z memdbNodeAddr) { | |||
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| db.count-- | |||
| db.size -= int(z.klen) | |||
| metrics.MemdbCount.Dec() | |||
| @@ -163,6 +164,8 @@ func (db *MemDB) Reset() { | |||
| db.vlogInvalid = false | |||
| db.size = 0 | |||
| db.count = 0 | |||
| metrics.MemdbSize.Set(0.0) | |||
| metrics.MemdbCount.Set(0.0) | |||
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Sorry I didn't understand it well. The metrics looks like global gauges. May there be many MemDB instances in a single process and they all Set values to the single gauge by themselves?
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I've mentioned it above and discussed it with @longfangsong , it's needed to be changed I think.
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#520 tracks the memory allocated to the arena. That could be reused here. |
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@longfangsong |
I plan to continue this pr after #520 is done. |
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@cfzjywxk @MyonKeminta do we want to continue this? |
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closing due to inactivity. Please reopen it if need. |
Add size and keys count metric for memdb