I'm running a Neo4J 5.3.0 community edition and tried to load the dump from https://github.com/neo4j-graph-examples/twitch. I managed to load the dump and migrate the database.
My question: how do I use the "twitch" database?
cosh#osmingestor:~$ sudo neo4j-admin database info
Database name: neo4j
Database in use: true
Last committed transaction id:-1
Store needs recovery: true
Database name: system
Database in use: true
Last committed transaction id:-1
Store needs recovery: true
Database name: twitch
Database in use: false
Store format version: record-aligned-1.1
Store format introduced in: 5.0.0
Last committed transaction id:62742
Store needs recovery: false
show databases doesn't show it for my user "neo4j":
neo4j#neo4j> show databases;
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| name | type | aliases | access | address | role | writer | requestedStatus | currentStatus | statusMessage | default | home | constituents |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| "neo4j" | "standard" | [] | "read-write" | "localhost:7687" | "primary" | TRUE | "online" | "online" | "" | TRUE | TRUE | [] |
| "system" | "system" | [] | "read-write" | "localhost:7687" | "primary" | TRUE | "online" | "online" | "" | FALSE | FALSE | [] |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
I tried to grant access to the database by executing:
neo4j#neo4j> grant all database PRIVILEGES ON DATABASES * TO neo4j;
Unsupported administration command: grant all database PRIVILEGES ON DATABASES * TO neo4j
Adding "neo4j" as the default admin did not help as well (was working though):
neo4j-admin dbms set-default-admin neo4j
Related
I'm stuck using TimescaleDB in Rails - everything works fine in development, but in my test suite I cannot insert any data.
What I tried
A) Use SQL schema dump
This causes the original error message I saw. It does create parts of the schema for TimescaleDB but not all of it. I have a hypertable but it's not working properly
B) Use Ruby schema dump
This lets me insert into my table but it's not a hypertable at all - the ruby syntax looses everything related to TimescaleDB and hypertables.
C) Migrate test database directly
I tried avoiding the schema.structure dump and load with the following:
$ rails db:drop
Dropped database 'my_app_development'
Dropped database 'my_app_test'
$ RAILS_ENV=test rails db:create
Created database 'my_app_test'
$ RAILS_ENV=test rails db:migrate
== 20200517164444 EnableTimescaledbExtension: migrating =======================
-- enable_extension("timescaledb")
WARNING:
WELCOME TO
_____ _ _ ____________
|_ _(_) | | | _ \ ___ \
| | _ _ __ ___ ___ ___ ___ __ _| | ___| | | | |_/ /
| | | | _ ` _ \ / _ \/ __|/ __/ _` | |/ _ \ | | | ___ \
| | | | | | | | | __/\__ \ (_| (_| | | __/ |/ /| |_/ /
|_| |_|_| |_| |_|\___||___/\___\__,_|_|\___|___/ \____/
Running version 1.7.0
For more information on TimescaleDB, please visit the following links:
1. Getting started: https://docs.timescale.com/getting-started
2. API reference documentation: https://docs.timescale.com/api
3. How TimescaleDB is designed: https://docs.timescale.com/introduction/architecture
Note: TimescaleDB collects anonymous reports to better understand and assist our users.
For more information and how to disable, please see our docs https://docs.timescaledb.com/using-timescaledb/telemetry.
-> 0.2315s
== 20200517164444 EnableTimescaledbExtension: migrated (0.2316s) ==============
== 20200517165027 CreateAccounts: migrating ===================================
-- create_table(:accounts)
-> 0.0095s
== 20200517165027 CreateAccounts: migrated (0.0095s) ==========================
== 20200517165103 CreateMetrics: migrating ====================================
-- create_table(:metrics)
-> 0.0116s
== 20200517165103 CreateMetrics: migrated (0.0117s) ===========================
== 20200517170842 CreateEvents: migrating =====================================
-- create_table(:events)
-> 0.0072s
-- remove_column(:events, :id)
-> 0.0020s
-- execute("SELECT create_hypertable('events', 'time');\n")
-> 0.0047s
== 20200517170842 CreateEvents: migrated (0.0142s) ============================
pg_dump: warning: there are circular foreign-key constraints on this table:
pg_dump: hypertable
pg_dump: You might not be able to restore the dump without using --disable-triggers or temporarily dropping the constraints.
pg_dump: Consider using a full dump instead of a --data-only dump to avoid this problem.
pg_dump: warning: there are circular foreign-key constraints on this table:
pg_dump: chunk
pg_dump: You might not be able to restore the dump without using --disable-triggers or temporarily dropping the constraints.
pg_dump: Consider using a full dump instead of a --data-only dump to avoid this problem.
But when running the test suite it is the same as attempt A.
Running the tests after actually prints this message a few times which makes me think that Rails auto-magically uses the structure.sql again to recreate the test DB:
psql:/home/axel/src/my_app/db/structure.sql:16: WARNING:
WELCOME TO
_____ _ _ ____________
|_ _(_) | | | _ \ ___ \
| | _ _ __ ___ ___ ___ ___ __ _| | ___| | | | |_/ /
| | | | _ ` _ \ / _ \/ __|/ __/ _` | |/ _ \ | | | ___ \
| | | | | | | | | __/\__ \ (_| (_| | | __/ |/ /| |_/ /
|_| |_|_| |_| |_|\___||___/\___\__,_|_|\___|___/ \____/
Running version 1.7.0
For more information on TimescaleDB, please visit the following links:
1. Getting started: https://docs.timescale.com/getting-started
2. API reference documentation: https://docs.timescale.com/api
3. How TimescaleDB is designed: https://docs.timescale.com/introduction/architecture
Note: TimescaleDB collects anonymous reports to better understand and assist our users.
For more information and how to disable, please see our docs https://docs.timescaledb.com/using-timescaledb/telemetry.
Error message
$ rails test
Running via Spring preloader in process 107937
Run options: --seed 29840
# Running:
E
Error:
Api::EventsControllerTest#test_POST_event_data_-_new_metric:
DRb::DRbRemoteError: PG::FeatureNotSupported: ERROR: invalid INSERT on the root table of hypertable "events"
HINT: Make sure the TimescaleDB extension has been preloaded.
(ActiveRecord::StatementInvalid)
app/controllers/api/events_controller.rb:5:in `create'
test/controllers/api/events_controller_test.rb:9:in `block in <class:EventsControllerTest>'
rails test test/controllers/api/events_controller_test.rb:8
Finished in 0.215286s, 4.6450 runs/s, 0.0000 assertions/s.
1 runs, 0 assertions, 0 failures, 1 errors, 0 skips
I have the feeling it's related to how Rails creates the test database using the schema.rb (for default config.active_record.schema_format = :ruby) or structure.sql (for config.active_record.schema_format = :sql.
I already tried both, the Ruby and SQL setting of the structure and neither works - development DB gets migrated correctly but test DB is not set up correctly.
In the two databases below (development and test) we can see the only difference is that the test DB is missing: Child tables: _timescaledb_internal._hyper_1_1_chunk
Development DB
$ psql -d my_app_development
psql (12.2)
Type "help" for help.
my_app_development=# SHOW shared_preload_libraries;
shared_preload_libraries
--------------------------
timescaledb
(1 row)
my_app_development=# insert into events (metric_id, time, value) VALUES (1, NOW(), 22);
INSERT 0 1
my_app_development=# \d+ events
Table "public.events"
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
-----------+-----------------------------+-----------+----------+---------+---------+--------------+-------------
metric_id | bigint | | | | plain | |
time | timestamp without time zone | | not null | | plain | |
value | numeric | | | | main | |
Indexes:
"events_time_idx" btree ("time" DESC)
Triggers:
ts_insert_blocker BEFORE INSERT ON events FOR EACH ROW EXECUTE FUNCTION _timescaledb_internal.insert_blocker()
Child tables: _timescaledb_internal._hyper_1_1_chunk
Access method: heap
Test DB
$ psql -d my_app_test
psql (12.2)
Type "help" for help.
my_app_test=# SHOW shared_preload_libraries;
shared_preload_libraries
--------------------------
timescaledb
(1 row)
my_app_test=# insert into events (metric_id, time, value) VALUES (1, NOW(), 22);
ERROR: invalid INSERT on the root table of hypertable "events"
HINT: Make sure the TimescaleDB extension has been preloaded.
my_app_test=# \d+ events
Table "public.events"
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
-----------+-----------------------------+-----------+----------+---------+---------+--------------+-------------
metric_id | bigint | | | | plain | |
time | timestamp without time zone | | not null | | plain | |
value | numeric | | | | main | |
Indexes:
"events_time_idx" btree ("time" DESC)
Triggers:
ts_insert_blocker BEFORE INSERT ON events FOR EACH ROW EXECUTE FUNCTION _timescaledb_internal.insert_blocker()
Access method: heap
ActiveRecord with SQL schema
CREATE EXTENSION IF NOT EXISTS timescaledb WITH SCHEMA public;
SET default_tablespace = '';
SET default_table_access_method = heap;
CREATE TABLE public.events (
metric_id bigint,
"time" timestamp without time zone NOT NULL,
value numeric
);
CREATE INDEX events_time_idx ON public.events USING btree ("time" DESC);
CREATE TRIGGER ts_insert_blocker BEFORE INSERT ON public.events FOR EACH ROW EXECUTE FUNCTION _timescaledb_internal.insert_blocker();
ActiveRecord with Ruby schema
ActiveRecord::Schema.define(version: 2020_05_17_170842) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
enable_extension "timescaledb"
create_table "events", id: false, force: :cascade do |t|
t.bigint "metric_id"
t.datetime "time", null: false
t.decimal "value"
t.index ["time"], name: "events_time_idx", order: :desc
end
end
Note: this looses the ts_insert_blocker trigger and lets me insert into the events table but it is not a hypertable anymore:
my_app_test=# \d+ events
Table "public.events"
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
-----------+-----------------------------+-----------+----------+---------+---------+--------------+-------------
metric_id | bigint | | | | plain | |
time | timestamp without time zone | | not null | | plain | |
value | numeric | | | | main | |
Indexes:
"events_time_idx" btree ("time" DESC)
Access method: heap
Additional information
Related question: Running an RSpec test suite against a TimescaleDB database with Rails 4.2 - The suggestions did not work for me and there is no accepted answer.
Version information:
Rails 6.0.3
Postgres 12.2
TimescaleDB 1.7.0
Edit 1
I added the following to my test/test_helper.rb similar to the workaround mentioned by #cstabru
def execute_create_hypertable(sql)
ActiveRecord::Base.connection.execute(sql)
rescue ActiveRecord::StatementInvalid => e
raise e unless e.message.include? 'is already a hypertable'
end
execute_create_hypertable <<~SQL
SELECT create_hypertable('events', 'time');
SQL
But maybe we can use something like SELECT create_hypertable('hypertable_name', 'time_field', if_not_exists => TRUE in an initializer instead of creating hypertables in DB migrations?
I ran into this as well, no matter which way i recreate the db schema (sql or ruby formats) the hyper table is not recreated as the timescale internal schema data is not exported.
Noting that when I restore using the sql format, it copies across the ts_insert_blocker trigger which indeed break inserts on the table with this error (I believe is due to the trigger function not being available)
PG::FeatureNotSupported: ERROR: invalid INSERT on the root table of hypertable "hypertable_name"
HINT: Make sure the TimescaleDB extension has been preloaded.
To fix the underlying issue (either sql or ruby formats) we can recreate the hypertable (and removing the trigger) manually via the following
DROP TRIGGER IF EXISTS ts_insert_blocker ON events;
DROP TRIGGER
SELECT create_hypertable('hypertable_name', 'time_field', if_not_exists => TRUE);
....
(1 row)
Now manually check for the hypertable existence since https://github.com/timescale/timescaledb/pull/862
SELECT * FROM timescaledb_information.hypertable;
I've added these DDL commands to my spec_helper.rb to ensure the test db uses an actual hypertable. I want to ensure the test db schema mirrors my production / staging setups.
config.before(:suite) do
# ensure the hypertable_name hypertable is setup correctly
ActiveRecord::Base.connection.execute(
"DROP TRIGGER IF EXISTS ts_insert_blocker ON hypertable_name;"
)
ActiveRecord::Base.connection.execute(
"SELECT create_hypertable('hypertable_name', 'time_field', if_not_exists => TRUE);"
)
has_hypertables_sql = "SELECT * FROM timescaledb_information.hypertable WHERE table_name = 'hypertable_name';"
if ActiveRecord::Base.connection.execute(has_hypertables_sql).to_a.empty?
raise "TimescaleDB missing hypertable on 'hypertable_name' table"
end
end
If folks find this useful I can look at extracting to a gem to help with schema restores for rails environments, https://github.com/timescale/timescaledb/issues/1916
In case somebody uses the DDL commands of cstabru's answer in spec_helper.rb and got the error PG::UndefinedTable: ERROR: Relation »timescaledb_information.hypertable« does not exist
From timescaledb version 2.0 on you have to use plural timescaledb_information.hypertables and the column name has changed too, so now you have to use hypertable_name instead of table_name.
config.before(:suite) do
# ensure the hypertable_name hypertable is setup correctly
ActiveRecord::Base.connection.execute(
"DROP TRIGGER IF EXISTS ts_insert_blocker ON hypertable_name;"
)
ActiveRecord::Base.connection.execute(
"SELECT create_hypertable('hypertable_name', 'time_field', if_not_exists => TRUE);"
)
has_hypertables_sql = "SELECT * FROM timescaledb_information.hypertables WHERE hypertable_name = 'hypertable_name';"
if ActiveRecord::Base.connection.execute(has_hypertables_sql).to_a.empty?
raise "TimescaleDB missing hypertable on 'hypertable_name' table"
end
end
I have two nodes "A" (primary) & "B". Each node have 3 resources. On node "B" i replace disks and after that i add each resource as secondary. Two resources successfully connect and sync, but with one resource i have issue. When on node "B" i stop this resource, node "A" shows
lv1 role:Primary
disk:UpToDate
b.host connection:Connecting
When i starts this resource on node "B", node "A" shows:
lv1 role:Primary
disk:UpToDate
b.host connection:StandAlone
and node "B" shows:
lv1 role:Secondary
disk:Inconsistent
a.host connection:Connecting
I try everything, remove/add resource, metadata on node "B", remove data, rebuild raid drbdadm connect lv1 --discard-my-data etc.
One difference between worked an broken resources is This node was a crashed primary, and has not seen its peer since
+--< Current data generation UUID >-
| +--< Bitmap's base data generation UUID >-
| | +--< younger history UUID >-
| | | +-< older history >-
V V V V
E43824C7BC375B4A:626476078D91E933:CC1DC3FAD143EDCC:E4E71860FBA887C2:1:1:1:1:0:0:0:0:0:0:0:1
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
-< Data consistency flag >--+ | | | | | | | | | | |
-< Data was/is currently up-to-date >--+ | | | | | | | | | |
-< Node was/is currently primary >--+ | | | | | | | | |
-< This node was a crashed primary, and has not seen its peer since >--+ | | | | | | | |
-< The activity-log was applied, the disk can be attached >--+ | | | | | | |
-< The activity-log was disabled, peer is completely out of sync >--+ | | | | | |
-< This node was primary when it lost quorum >--+ | | | | |
-< Node was/is currently connected >--+ | | | |
-< The peer's disk was out-dated or inconsistent >--+ | | |
-< A fence policy other the dont-care was used >--+ | |
-< Node was in the progress of marking all blocks as out of sync >--+ |
-< At least once we saw this node with a backing device attached >--+
Any ideas how i can fix it?
UPD: Find new differences a kernel: drbd lv1/0 drbd1 b.host: The peer's disk size is too small! (999671944 < 1000196216 sectors)
In my case on node "A" (primary) i have LVM, on node "B" i have MDRAID. This differences give me difference in resource size in 524 272 sectors. What i do to save my data. I run both resources in primary mode, mount and copy data from "A" to "B", then i rebuild node "A" to MDRAID and sync resources.
This is my first time using PostgreSQL for production.
I made a database blog_production with username blog_production and generated password from gemfile capistrano-postgresql. Once it is generated, I tried to delete database blog_production with this command from terminal:
$ sudo -u postgres dropdb blog_production
After that I tried to delete user blog_production with this command:
$ sudo -u postgres droprole blog_production
And it returned dropuser: removal of role "blog_production" failed: ERROR: cache lookup failed for database 16417
1.) Why is this happening?
2.) I also tried to delete from psql using DELETE FROM pg_roles WHERE rolname='blog_production' but it returned the same error (cache lookup failed)
3.) How do I solve this problem?
Thank you.
Additional Information
PostgreSQL Version
PostgreSQL 9.1.15 on x86_64-unknown-linux-gnu, compiled by gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 64-bit
(1 row)
select * from pg_shdepend where dbid = 16417;
dbid | classid | objid | objsubid | refclassid | refobjid | deptype
-------+---------+-------+----------+------------+----------+---------
16417 | 1259 | 16419 | 0 | 1260 | 16418 | o
16417 | 1259 | 16426 | 0 | 1260 | 16418 | o
16417 | 1259 | 16428 | 0 | 1260 | 16418 | o
(3 rows)
select * from pg_database where oid = 16417;
datname | datdba | encoding | datcollate | datctype | datistemplate | datallowconn | datconnlimit | datlastsysoid | datfrozenxid | dattablespace | datacl
---------+--------+----------+------------+----------+---------------+--------------+--------------+---------------+--------------+---------------+--------
(0 rows)
select * from pg_authid where rolname = 'blog_production'
rolname | rolsuper | rolinherit | rolcreaterole | rolcreatedb | rolcatupdate | rolcanlogin | rolreplication | rolconnlimit | rolpassword | rolvaliduntil
-----------------+----------+------------+---------------+-------------+--------------+-------------+----------------+--------------+-------------------------------------+---------------
blog_production | f | t | f | f | f | t | f | -1 | md5d4d2f8789ab11ba2bd019bab8be627e6 |
(1 row)
Somehow the DROP database; didn't drop the shared dependencies correctly. PostgreSQL still thinks that your user owns three tables in the database you dropped.
Needless to say this should not happen; it's almost certainly a bug, though I don't know how we'd even begin tracking it down unless you know exactly what commands you ran etc to get to this point, right from creating the DB.
If the PostgreSQL install's data isn't very big and if you can share the contents, can I get you to stop the database server and make a tarball of the whole database directory, then send it to me? I'd like to see if I can tell what happened to get you to this point.
Send a dropbox link to craig#2ndquadrant.com . Just:
sudo service postgresql stop
sudo tar cpjf ~abrahamks/abrahamks-postgres.tar.gz \
/var/lib/postgresql/9.1/main \
/etc/postgresql/9.1/main \
/var/log/postgresql/postgresql-9.1-main-*.
/usr/lib/postgresql/9.1
sudo chown abrahamks ~abrahamks/abrahamks-postgres.tar.gz
and upload abrahamks-postgres.tar.gz from your home folder.
Replace abrahamks with your username on your system. You might need to adjust the paths above if I'm misremembering where the PostgreSQL data lives on Debian-derived systems.
Note that this contains all your databases not just the one that was an issue, and it also contains your PostgreSQL user accounts.
(If you're going to send me a copy, do so before continuing):
Anyway, since the database is dropped, it is safe to manually remove the dependencies that should've been removed by DROP DATABASE:
DELETE FROM pg_shdepend WHERE dbid = 16417
It should then be possible to DROP USER blog_production;
I am finding trouble in why my query in secondary indexed column in cassandra getting rpc timeout.
Here is my details about the cassandra and table
[cqlsh 4.1.1 | Cassandra 2.0.7 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
cqlsh:master_hub_development> describe table service_hubs;
CREATE TABLE service_hubs (
id uuid,
host text,
hub_name text,
os text,
owner text,
pubkey text,
service_type text,
trust int,
PRIMARY KEY (id)
) WITH
bloom_filter_fp_chance=0.010000 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.000000 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.100000 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor'};
CREATE INDEX service_hubs_host_idx ON service_hubs (host);
CREATE INDEX service_hubs_hub_name_idx ON service_hubs (hub_name);
CREATE INDEX service_hubs_os_idx ON service_hubs (os);
CREATE INDEX service_hubs_owner_idx ON service_hubs (owner);
CREATE INDEX service_hubs_pubkey_idx ON service_hubs (pubkey);
CREATE INDEX service_hubs_service_type_idx ON service_hubs (service_type);
CREATE INDEX service_hubs_trust_idx ON service_hubs (trust);
cqlsh:master_hub_development> select * from service_hubs;
id | host | hub_name | os | owner | pubkey | service_type | trust
--------------------------------------+----------------+--------------------+--------+---------------+--------+--------------+-------
b9d9bd06-e006-11e3-a1e2-3382b7d578d2 | localhost:3001 | HUB:Darknetdb | Mac os | darknet_admin | null | darknetdb | 90
b9d74918-e006-11e3-a1e2-3382b7d578d2 | localhost:3000 | HUB:Darknetbitcoin | Mac os | darknet_admin | null | bitcoin | 90
b9da9b2c-e006-11e3-a1e2-3382b7d578d2 | localhost:3002 | HUB:Darknetemail | Mac os | darknet_admin | null | email | 90
b9db8596-e006-11e3-a1e2-3382b7d578d2 | localhost:3003 | HUB:Darknetftp | Mac os | darknet_admin | null | ftp | 90
(4 rows)
cqlsh:master_hub_development> select * from service_hubs where host='localhost:3001';
id | host | hub_name | os | owner | pubkey | service_type | trust
--------------------------------------+----------------+---------------+--------+---------------+--------+--------------+-------
b9d9bd06-e006-11e3-a1e2-3382b7d578d2 | localhost:3001 | HUB:Darknetdb | Mac os | darknet_admin | null | darknetdb | 90
(1 rows)
cqlsh:master_hub_development> select * from service_hubs where service_type='darknetdb';
Request did not complete within rpc_timeout.
Here we can see that the query on secondary index column host gets succeeded but the similar query on service_type gets rpc_timeout error.
I am not able to find the reason behind it why it rpc_timeouted in this query.
select * from service_hubs where service_type='darknetdb';
Thanks
I want to store a simple active record object using memcached. I know I need to first convert the object to JSON before saving it to memcached my question is how I can pull it out again, deserialize it and use it as an activerecord relation. Do I have to make a custom parser the JSON or am I overlooking some drop dead easy solution?
The active record object looks like this:
+------+-----+-----------+---------------------------------+---------------------+-------+
| id | ppl | exclusive | name | price | spots |
+------+-----+-----------+---------------------------------+---------------------+-------+
| 8948 | 12 | false | 12 Bed Mixed Dorm | 9.0000000000000000 | 12 |
| 8947 | 10 | false | 10 Bed Mixed Dorm | 9.5000000000000000 | 10 |
| 8946 | 6 | false | 6 Bed Mixed Dorm | 10.0000000000000000 | 6 |
| 8945 | 4 | false | Basic 4 Bed Mixed Dorm | 10.0000000000000000 | 4 |
| 8944 | 2 | true | Twin Private Shared Bathroom | 12.0000000000000000 | 1 |
| 8943 | 1 | true | Standard Single Private Ensuite | 15.0000000000000000 | 1 |
+------+-----+-----------+---------------------------------+---------------------+-------+
You shouldn't don't need to worry about the serialization -- in almost all cases, this can be handled for you:
#Gemfile
gem install dalli
#config/environments/production.rb
config.cache_store = :dalli_store, '127.0.0.1' #use memcached
#Get id 1245 from model_names
Rails.cache.fetch("ModelName#1245") do
ModelName.find(1245)
end