github.com/m3db/m3@v1.5.1-0.20231129193456-75a402aa583b/src/dbnode/client/fetch_state_pool.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package client
    22  
    23  import (
    24  	"time"
    25  
    26  	"github.com/m3db/m3/src/dbnode/topology"
    27  	"github.com/m3db/m3/src/x/instrument"
    28  	"github.com/m3db/m3/src/x/pool"
    29  	"github.com/m3db/m3/src/x/sampler"
    30  
    31  	"go.uber.org/zap"
    32  )
    33  
    34  type fetchStatePool interface {
    35  	Init()
    36  	Get() *fetchState
    37  	Put(*fetchState)
    38  	MaybeLogHostError(hostErr maybeHostFetchError)
    39  }
    40  
    41  type fetchStatePoolImpl struct {
    42  	pool pool.ObjectPool
    43  
    44  	instrumentOpts      instrument.Options
    45  	logger              *zap.Logger
    46  	logHostErrorSampler *sampler.Sampler
    47  }
    48  
    49  func newFetchStatePool(
    50  	opts pool.ObjectPoolOptions,
    51  	logger *zap.Logger,
    52  	logHostErrorSampler *sampler.Sampler,
    53  ) fetchStatePool {
    54  	return &fetchStatePoolImpl{
    55  		pool:                pool.NewObjectPool(opts),
    56  		logger:              logger,
    57  		logHostErrorSampler: logHostErrorSampler,
    58  	}
    59  }
    60  
    61  func (p *fetchStatePoolImpl) Init() {
    62  	p.pool.Init(func() interface{} {
    63  		return newFetchState(p)
    64  	})
    65  }
    66  
    67  func (p *fetchStatePoolImpl) Get() *fetchState {
    68  	return p.pool.Get().(*fetchState)
    69  }
    70  
    71  func (p *fetchStatePoolImpl) Put(f *fetchState) {
    72  	p.pool.Put(f)
    73  }
    74  
    75  func (p *fetchStatePoolImpl) MaybeLogHostError(hostErr maybeHostFetchError) {
    76  	if hostErr.err == nil {
    77  		// No error, this is an expected code path when host request doesn't
    78  		// encounter an error.
    79  		return
    80  	}
    81  
    82  	if !p.logHostErrorSampler.Sample() {
    83  		return
    84  	}
    85  
    86  	p.logger.Warn("sampled error fetching from host (may not lead to consistency result error)",
    87  		zap.Stringer("host", hostErr.host),
    88  		zap.Duration("reqRespTime", hostErr.reqRespTime),
    89  		zap.Error(hostErr.err))
    90  }
    91  
    92  type maybeHostFetchError struct {
    93  	// Note: both these fields should be set always.
    94  	host        topology.Host
    95  	reqRespTime time.Duration
    96  
    97  	// Error field is optionally set when there is actually an error.
    98  	err error
    99  }