minio/cmd/server-rlimit-nix.go
Harshavardhana b363709c11 caching: Optimize memory allocations. (#3405)
This change brings in changes at multiple places

 - Reuse buffers at almost all locations ranging
   from rpc, fs, xl, checksum etc.
 - Change caching behavior to disable itself
   under low memory conditions i.e < 8GB of RAM.
 - Only objects cached are of size 1/10th the size
   of the cache for example if 4GB is the cache size
   the maximum object size which will be cached
   is going to be 400MB. This change is an
   optimization to cache more objects rather
   than few larger objects.
 - If object cache is enabled default GC
   percent has been reduced to 20% in lieu
   with newly found behavior of GC. If the cache
   utilization reaches 75% of the maximum value
   GC percent is reduced to 10% to make GC
   more aggressive.
 - Do not use *bytes.Buffer* due to its growth
   requirements. For every allocation *bytes.Buffer*
   allocates an additional buffer for its internal
   purposes. This is undesirable for us, so
   implemented a new cappedWriter which is capped to a
   desired size, beyond this all writes rejected.

Possible fix for #3403.
2016-12-08 20:35:07 -08:00

84 lines
2.7 KiB
Go

// +build !windows,!plan9
/*
* Minio Cloud Storage, (C) 2016 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"syscall"
"github.com/minio/minio/pkg/sys"
)
// For all unixes we need to bump allowed number of open files to a
// higher value than its usual default of '1024'. The reasoning is
// that this value is too small for a server.
func setMaxOpenFiles() error {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return err
}
// Set the current limit to Max, it is usually around 4096.
// TO increase this limit further user has to manually edit
// `/etc/security/limits.conf`
rLimit.Cur = rLimit.Max
return syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
}
// Set max memory used by minio as a process, this value is usually
// set to 'unlimited' but we need to validate additionally to verify
// if any hard limit is set by the user, in such a scenario would need
// to reset the global max cache size to be 80% of the hardlimit set
// by the user. This is done to honor the system limits and not crash.
func setMaxMemory() error {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_AS, &rLimit)
if err != nil {
return err
}
// Set the current limit to Max, it is default 'unlimited'.
// TO decrease this limit further user has to manually edit
// `/etc/security/limits.conf`
rLimit.Cur = rLimit.Max
err = syscall.Setrlimit(syscall.RLIMIT_AS, &rLimit)
if err != nil {
return err
}
err = syscall.Getrlimit(syscall.RLIMIT_AS, &rLimit)
if err != nil {
return err
}
// Validate if rlimit memory is set to lower
// than max cache size. Then we should use such value.
if uint64(rLimit.Cur) < globalMaxCacheSize {
globalMaxCacheSize = uint64(float64(50*rLimit.Cur) / 100)
}
// Make sure globalMaxCacheSize is less than RAM size.
stats, err := sys.GetStats()
if err != nil && err != sys.ErrNotImplemented {
return err
}
// If TotalRAM is >= minRAMSize we proceed to enable cache.
// cache is always 50% of the totalRAM.
if err == nil && stats.TotalRAM >= minRAMSize {
globalMaxCacheSize = uint64(float64(50*stats.TotalRAM) / 100)
}
return nil
}