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Letter to Summoners Jun 2020

Previous Letter to Summoners (Mar 2020):


Dear Summoners, 


Thank you for your great support to TOS Team. From Mar 2020 to now, we’ve made the following adjustments:


Completed Tasks

1. Server Optimization 

– Enhance the capability of data servers

– Increase the speed of each database from 3000 writes/sec to 12000 writes/sec

– Upon optimization, the servers on v19.1 take 7 hours less to be stable compared to v19.0


2. Reduce Loading Time

– The test result showed that the loading time reduced by approx. 24% in v19.0 compared to v18.4


Ongoing Tasks

1. New Chatroom System

– New UI

– More channels with sticker function 


2. Improve Story Mode Dialogue UI

– Adjust characters’ resolution and fade-in positions to have a better UI


Completed Tasks

(1.1) Server Optimization 


As mentioned in the previous letter, we would take data records and analysis systems from game servers into standalone servers and databases in order to alleviate the burden of the system. The standalone servers and databases will be used when needed to reduce the CPU and RAM usage of API Server. With the enhancement of the database server capabilities, more traffic loads can be handled at the same time.


Besides, we’ve upgraded the servers also. In the latest version, the speed of each database has sped up from 3000 writes/sec to 12000 writes/sec. The queuing time on the version update of v18.4 and 19.0 was approx. 4.6 hours and 7 hours respectively. After the server upgrade, the servers can handle a large amount of logins on the version update of v19.1 without any queuing time. When the black-gold character “Pandora” was released, the servers were able to remain stable.


(1.2) Reduce Loading Time


As the in-game content becomes richer, the loading time will take much longer.


In v19.0, the login process has been optimized to remove unnecessary logics. We also categorized the data downloaded during the login to store the monsters and some data in the cache of the mobile phone. During the login, if a part of the data has not been changed, players are not required to download the update. This reduces approx. 30% of data consumption to increased loading speed.


We’ve conducted tests on iPhone 6 Plus, Samsung Galaxy S5, Samsung Note 8 and ASUS Zenfone 3. The loading time of v19.0 reduced by 16-32% (24% in average) compared to v18.4.




2. Ongoing Tasks

(2.1) New Chatroom


To let players chat and exchange info with friends conveniently, we’re developing a new chatroom system. 


The new UI of the chatroom will keep all those functions of the current chatroom, and support different screen ratios of the mobile phones. Apart from guild chatroom, more channels will be added. Through the default channels, you can share your walkthroughs, discussions with friends. New sticker function will be added.


(2.2) Improve Story Mode Dialogue UI


We hope to solve the low-res images, unbalanced positions and dialogue frame, etc. So we will re-design the UI to make it look better.


3. Game Data

(3.1) Hours of Issues


In v18.4, some players were unable to login as our game servers were attacked. We’ve stepped up the defense on the night for this emergency. In v19.0, DNS error has affected the servers, and resumed service after 12 mins. In v19.1, a setting error occurred resulting in the login error. From 8 – 16 Jun, a small amount of players failed to login due to client or in-game data errors.




* The hours of issues do not include the hours of those players who failed to connect the servers (Error Code -1001 & -1007) from 8-16 Jun.


v18.4 Issues

– 3 attacks from hackers on 11 Apr 2020. Players could login after solving the issue on the same night.

1st: 16:48 – 16:58 (10 mins)

2nd: 18:41 – 18:45 (4 mins)

3rd: 19:22 – 19:36 (14 mins)


v19.0 Issues

– 16 Apr 2020 20:56 – 21:08 (12 mins)

Players failed to download in-game data and login due to DNS error. After the emergency database booting of CDN, the service resumed.


v19.1 Issues

– 8 Jun 2020 21:00 – 21:30 (30 mins)

Players failed to login due to setting errors of the servers. It resumed service within 30 mins.


– 8 Jun 2020 – 11 Jun 2020 

Upon v19.1, some players were unable to connect the servers during login (Error Code -1001). We’ve collected some cases and found that the connection system updated by the client would be abnormal in a specific network. The issue was fixed on 11 Jun.


– 11 Jun 2020 – 16 Jun 2020

Upon v19.11, some players have reported the Error Code -1007, due to in-game data errors. When the character info was unable to completely remove after deleting the character, or the character’s outfit has been changed when choosing ally in v19.1, it would lead to data error. The issue was fixed on 16 Jun.


– 23 Jun 2020 18:02 – 18:18 (16 mins)

Back-side service has lowered the database capabilities. The service was back to normal after shutting down the affected servers.


(3.2) Number of Known & Fixed Issues




Highlights on Fixed & Known Issues