e9eda7e7c8
* cache: add sharded cache implementation Add Cache impl and a few tests. This cache is 256-way sharded, mainly so each shard has it's own lock. The main cache structure is a readonly jump plane into the right shard. This should remove the single lock contention on the main lock and provide more concurrent throughput - Obviously this hasn't been tested or measured. The key into the cache was made a uint32 (hash.fnv) and the hashing op is not using strings.ToLower anymore remove any GC in that code path. * here too * Minimum shard size * typos * blurp * small cleanups no defer * typo * Add freq based on Johns idea * cherry-pick conflict resolv * typo * update from early code review from john * add prefetch to the cache * mw/cache: add prefetch * remove println * remove comment * Fix tests * Test prefetch in setup * Add start of cache * try add diff cache options * Add hacky testcase * not needed * allow the use of a percentage for prefetch If the TTL falls below xx% do a prefetch, if the record was popular. Some other fixes and correctly prefetch only popular records.
54 lines
1.4 KiB
Go
54 lines
1.4 KiB
Go
package cache
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import (
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"fmt"
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"testing"
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"time"
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"github.com/coredns/coredns/middleware"
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"github.com/coredns/coredns/middleware/pkg/cache"
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"github.com/coredns/coredns/middleware/pkg/dnsrecorder"
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"github.com/coredns/coredns/middleware/test"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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)
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var p = false
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func TestPrefetch(t *testing.T) {
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c := &Cache{Zones: []string{"."}, pcap: defaultCap, ncap: defaultCap, pttl: maxTTL, nttl: maxTTL}
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c.pcache = cache.New(c.pcap)
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c.ncache = cache.New(c.ncap)
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c.prefetch = 1
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c.duration = 1 * time.Second
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c.Next = PrefetchHandler(t, dns.RcodeSuccess, nil)
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ctx := context.TODO()
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req := new(dns.Msg)
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req.SetQuestion("lowttl.example.org.", dns.TypeA)
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rec := dnsrecorder.New(&test.ResponseWriter{})
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c.ServeDNS(ctx, rec, req)
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p = true // prefetch should be true for the 2nd fetch
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c.ServeDNS(ctx, rec, req)
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}
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func PrefetchHandler(t *testing.T, rcode int, err error) middleware.Handler {
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return middleware.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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m := new(dns.Msg)
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m.SetQuestion("lowttl.example.org.", dns.TypeA)
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m.Response = true
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m.RecursionAvailable = true
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m.Answer = append(m.Answer, test.A("lowttl.example.org. 80 IN A 127.0.0.53"))
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if p != w.(*ResponseWriter).prefetch {
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err = fmt.Errorf("cache prefetch not equal to p: got %t, want %t", p, w.(*ResponseWriter).prefetch)
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t.Fatal(err)
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}
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w.WriteMsg(m)
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return rcode, err
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})
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}
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