ctubbsii commented on code in PR #411:
URL: https://github.com/apache/accumulo-website/pull/411#discussion_r1431967385
##########
_docs-2/troubleshooting/advanced.md:
##########
@@ -249,21 +249,29 @@ metadata table!), the following process can be followed
to create a valid, empty
WAL file. Run the following commands as the Accumulo unix user (to ensure that
the proper file permissions in HDFS)
- $ echo -n -e '--- Log File Header (v2) ---\x00\x00\x00\x00' > empty.wal
+```
+$ UUID=$(uuidgen); \
+echo -n -e '--- Log File Header (v4) ---U+1F47B$'"${UUID}"'\x00\x00\x00\x00' >
"${UUID}".wal; \
+echo 'created: '"${UUID}"'.wal'
Review Comment:
I'm a little surprised that the UUID is baked into the file as well as the
file name. In any case, I tried to copy and paste your example, and it didn't
work for me. The formatting was off. I think these changes make it easier to
copy/paste, and also simplifies things by removing unnecessary braces:
```suggestion
```sh
UUID=$(uuidgen); echo -n -e '--- Log File Header (v4)
---U+1F47B$'"$UUID"'\x00\x00\x00\x00' >"$UUID".wal
```
##########
_docs-2/troubleshooting/advanced.md:
##########
@@ -249,21 +249,29 @@ metadata table!), the following process can be followed
to create a valid, empty
WAL file. Run the following commands as the Accumulo unix user (to ensure that
the proper file permissions in HDFS)
- $ echo -n -e '--- Log File Header (v2) ---\x00\x00\x00\x00' > empty.wal
+```
+$ UUID=$(uuidgen); \
+echo -n -e '--- Log File Header (v4) ---U+1F47B$'"${UUID}"'\x00\x00\x00\x00' >
"${UUID}".wal; \
+echo 'created: '"${UUID}"'.wal'
+```
-The above creates a file with the text "--- Log File Header (v2) ---" and then
-four bytes. You should verify the contents of the file with a hexdump tool.
+The above creates a file with the text "--- Log File Header (v4) ---" a
unicode character to flag no decryption
+parameters, a UUID and then four bytes. The file created will be `[uuid]`.wal
and the name is echoed to the command
+line. You should verify the contents of the file with a hexdump tool.
-Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS
-with the empty WAL.
+Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS with the empty WAL for the
+tserver / host pair with the following hdfs commands:
- $ hdfs dfs -moveFromLocal empty.wal /user/accumulo/empty.wal
- $ hdfs dfs -mv /user/accumulo/empty.wal
/accumulo/wal/tserver-4.example.com+10011/26abec5b-63e7-40dd-9fa1-b8ad2436606e
+ $ hdfs dfs -moveFromLocal [uuid].wal /user/accumulo/[uuid].wal
+ $ hdfs dfs -mv /user/accumulo/[uuid].wal
/accumulo/wal/[tserver+port]/[uuid]
-After the corrupt WAL file has been replaced, the system should automatically
recover.
-It may be necessary to restart the Accumulo Manager process as an exponential
-backup policy is used which could lead to a long wait before Accumulo will
-try to re-load the WAL file.
+Note:
+- the `+` separator for port.
+- the wal file is the uuid, without an extension
+
+After the corrupt WAL file has been replaced, the system should automatically
recover. It may be necessary to restart
+the Accumulo Manager process as an exponential backup policy is used which
could lead to a long wait before Accumulo
Review Comment:
```suggestion
the Accumulo Manager process to reduce the recovery time, because an
exponential backup policy is used which could lead to a long wait before
Accumulo
```
##########
_docs-2/troubleshooting/advanced.md:
##########
@@ -249,21 +249,29 @@ metadata table!), the following process can be followed
to create a valid, empty
WAL file. Run the following commands as the Accumulo unix user (to ensure that
the proper file permissions in HDFS)
- $ echo -n -e '--- Log File Header (v2) ---\x00\x00\x00\x00' > empty.wal
+```
+$ UUID=$(uuidgen); \
+echo -n -e '--- Log File Header (v4) ---U+1F47B$'"${UUID}"'\x00\x00\x00\x00' >
"${UUID}".wal; \
+echo 'created: '"${UUID}"'.wal'
+```
-The above creates a file with the text "--- Log File Header (v2) ---" and then
-four bytes. You should verify the contents of the file with a hexdump tool.
+The above creates a file with the text "--- Log File Header (v4) ---" a
unicode character to flag no decryption
+parameters, a UUID and then four bytes. The file created will be `[uuid]`.wal
and the name is echoed to the command
+line. You should verify the contents of the file with a hexdump tool.
-Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS
-with the empty WAL.
+Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS with the empty WAL for the
+tserver / host pair with the following hdfs commands:
- $ hdfs dfs -moveFromLocal empty.wal /user/accumulo/empty.wal
- $ hdfs dfs -mv /user/accumulo/empty.wal
/accumulo/wal/tserver-4.example.com+10011/26abec5b-63e7-40dd-9fa1-b8ad2436606e
+ $ hdfs dfs -moveFromLocal [uuid].wal /user/accumulo/[uuid].wal
+ $ hdfs dfs -mv /user/accumulo/[uuid].wal
/accumulo/wal/[tserver+port]/[uuid]
Review Comment:
````suggestion
```sh
hdfs dfs -moveFromLocal "$UUID.wal" "/user/accumulo/$UUID.wal"
hdfs dfs -mv "/user/accumulo/$UUID.wal" "/accumulo/wal/[tserver+port]/$UUID"
```
````
##########
_docs-2/troubleshooting/advanced.md:
##########
@@ -249,21 +249,29 @@ metadata table!), the following process can be followed
to create a valid, empty
WAL file. Run the following commands as the Accumulo unix user (to ensure that
the proper file permissions in HDFS)
- $ echo -n -e '--- Log File Header (v2) ---\x00\x00\x00\x00' > empty.wal
+```
+$ UUID=$(uuidgen); \
+echo -n -e '--- Log File Header (v4) ---U+1F47B$'"${UUID}"'\x00\x00\x00\x00' >
"${UUID}".wal; \
+echo 'created: '"${UUID}"'.wal'
+```
-The above creates a file with the text "--- Log File Header (v2) ---" and then
-four bytes. You should verify the contents of the file with a hexdump tool.
+The above creates a file with the text "--- Log File Header (v4) ---" a
unicode character to flag no decryption
+parameters, a UUID and then four bytes. The file created will be `[uuid]`.wal
and the name is echoed to the command
+line. You should verify the contents of the file with a hexdump tool.
Review Comment:
```suggestion
This will create a file named `[uuid].wal` containing `--- Log File Header
(v4) ---`, a unicode
character to flag no decryption parameters, a UUID (the same as the file
name), and then four bytes.
You should modify this command to use a specific UUID if you need to replace
a particular file with
that UUID as its name. This command should work in most modern shells, but
because shell features
can vary, you should verify the contents of the file with a hexdump tool.
```
##########
_docs-2/troubleshooting/advanced.md:
##########
@@ -249,21 +249,29 @@ metadata table!), the following process can be followed
to create a valid, empty
WAL file. Run the following commands as the Accumulo unix user (to ensure that
the proper file permissions in HDFS)
- $ echo -n -e '--- Log File Header (v2) ---\x00\x00\x00\x00' > empty.wal
+```
+$ UUID=$(uuidgen); \
+echo -n -e '--- Log File Header (v4) ---U+1F47B$'"${UUID}"'\x00\x00\x00\x00' >
"${UUID}".wal; \
+echo 'created: '"${UUID}"'.wal'
+```
-The above creates a file with the text "--- Log File Header (v2) ---" and then
-four bytes. You should verify the contents of the file with a hexdump tool.
+The above creates a file with the text "--- Log File Header (v4) ---" a
unicode character to flag no decryption
+parameters, a UUID and then four bytes. The file created will be `[uuid]`.wal
and the name is echoed to the command
+line. You should verify the contents of the file with a hexdump tool.
-Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS
-with the empty WAL.
+Then, place this empty WAL in HDFS and then replace the corrupt WAL file in
HDFS with the empty WAL for the
+tserver / host pair with the following hdfs commands:
- $ hdfs dfs -moveFromLocal empty.wal /user/accumulo/empty.wal
- $ hdfs dfs -mv /user/accumulo/empty.wal
/accumulo/wal/tserver-4.example.com+10011/26abec5b-63e7-40dd-9fa1-b8ad2436606e
+ $ hdfs dfs -moveFromLocal [uuid].wal /user/accumulo/[uuid].wal
+ $ hdfs dfs -mv /user/accumulo/[uuid].wal
/accumulo/wal/[tserver+port]/[uuid]
-After the corrupt WAL file has been replaced, the system should automatically
recover.
-It may be necessary to restart the Accumulo Manager process as an exponential
-backup policy is used which could lead to a long wait before Accumulo will
-try to re-load the WAL file.
+Note:
+- the `+` separator for port.
+- the wal file is the uuid, without an extension
+
+After the corrupt WAL file has been replaced, the system should automatically
recover. It may be necessary to restart
+the Accumulo Manager process as an exponential backup policy is used which
could lead to a long wait before Accumulo
+will try to re-load the WAL file.
Review Comment:
```suggestion
will try to reload the WAL file.
```
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