There is a fundamental race condition in `newErasureServerPools`, where setObjectLayer is
called before the poolMeta has been loaded/populated.
We add a placeholder value to this field but disable all saving of the value, so we don't risk
overwriting the value on disk. Once the value has been loaded or created, it is replaced with
the proper value, which will also be saved.
Also fixes various accesses of `poolMeta` that were done without locks.
We make the `poolMeta.IsSuspended` return false, even if we shouldn't risk out-of-bounds
reads anymore.
If target went offline while MinIO was down, error once
while trying to send message. If target goes offline during
MinIO server running, it already comes through ping() call
and errors out if target offline.
Signed-off-by: Shubhendu Ram Tripathi <shubhendu@minio.io>
if erasure upgrade is needed rely on the in-memory
values, instead of performing a "DiskInfo()" call.
https://brendangregg.com/blog/2016-09-03/sudden-disk-busy.html
for HDDs these are problematic, lets avoid this because
there is no value in "being" absolutely strict here
in terms of parity. We are okay to increase parity
as we see based on the in-memory online/offline ratio.
Several callers to putObjectTar may be fighting to set sc. Move the write out of the loop.
Use static resp, and request elements.
Fixes tests with -race:
```
WARNING: DATA RACE
Read at 0x00c01cd680e0 by goroutine 691354:
github.com/minio/minio/cmd.objectAPIHandlers.PutObjectExtractHandler.func1()
e:/gopath/src/github.com/minio/minio/cmd/object-handlers.go:2130 +0x149
github.com/minio/minio/cmd.untar.func1()
e:/gopath/src/github.com/minio/minio/cmd/untar.go:250 +0x2b6
github.com/minio/minio/cmd.untar.func8()
e:/gopath/src/github.com/minio/minio/cmd/untar.go:261 +0xa4
Previous write at 0x00c01cd680e0 by goroutine 691352:
github.com/minio/minio/cmd.objectAPIHandlers.PutObjectExtractHandler.func1()
e:/gopath/src/github.com/minio/minio/cmd/object-handlers.go:2131 +0x15d
github.com/minio/minio/cmd.untar.func1()
e:/gopath/src/github.com/minio/minio/cmd/untar.go:250 +0x2b6
github.com/minio/minio/cmd.untar.func8()
e:/gopath/src/github.com/minio/minio/cmd/untar.go:261 +0xa4
```
Calling unfreezeServices twice results in panic:
```
panic: "POST /minio/peer/v32/signalservice?signal=4&sub-sys=": close of nil channel
goroutine 14703 [running]:
runtime/debug.Stack()
runtime/debug/stack.go:24 +0x65
github.com/minio/minio/cmd.setCriticalErrorHandler.func1.1()
github.com/minio/minio/cmd/generic-handlers.go:549 +0x8e
panic({0x27c3020, 0x4c9b370})
runtime/panic.go:884 +0x212
github.com/minio/minio/cmd.unfreezeServices()
github.com/minio/minio/cmd/service.go:112 +0xc7
github.com/minio/minio/cmd.(*peerRESTServer).SignalServiceHandler(0x0?, {0x4cb6af0, 0xc010b96420}, 0xc01affab00)
github.com/minio/minio/cmd/peer-rest-server.go:837 +0x13a
net/http.HandlerFunc.ServeHTTP(...)
```
If the function was called a second time `val` would not be nil, but the returned channel `ch` would be, causing the panic.
Check the channel isn't nil and also use Swap for an atomic swap instead of 2 separate operations (though we are in a mutex).
Disk level O_DIRECT support checking at xl storage initialization was
conditional on a config setting being enabled. (This never took effect
because config initialization happens after ObjectLayer is ready.) This
is not necessary as the config setting is dynamic - O_DIRECT should be
enabled via runtime config. So we need to do the disk level support
check regardless of the config setting.
- Trace needs higher buffered channels than 4000 to ensure
when we run `mc admin trace -a` it captures all information
sufficiently.
- Listen event notification needs the event channel to be
`apiRequestsMaxPerNode` * number of nodes
Currently, the retry is not fully used when there is no backup copy of
the data usage; use 5 retry attempts when we don't have any valid data,
new or backup, unless we have seen an un-recognized error.
comment in the code provides more detailed explanation
on what this PR entails and its assumptions.
this PR reduces the amount of listing() by an order
of magnitude, however there are other such calls that
still needs further optimization that shall be done
in subsequent PRs.
Add a new endpoint for "resource" metrics `/v2/metrics/resource`
This should return system metrics related to drives, network, CPU and
memory. Except for drives, other metrics should have corresponding "avg"
and "max" values also.
Reuse the real-time feature to capture the required data,
introducing CPU and memory metrics in it.
Collect the data every minute and keep updating the average and max values
accordingly, returning the latest values when the API is called.
without this the rename2() can rename the previous dataDir
causing issues for different versions of the object, only
latest version is preserved due to this bug.
Added healing code to ensure recovery of such content.
